Hard-disk drives, or HDDs, are mechanical devices. They work by recording data on a spinning magnetic platter or platters. By contrast, solid-state drives are made of chips and have no moving parts. They are close cousins to the so-called flash memory used in digital cameras, cellphones and smaller-capacity music players. They record data to special memory chips that retain their contents even when the device is turned off.

Solid-state drives have some key advantages. Because they lack moving parts, they are faster, draw less power, are harder to damage and are quieter than hard drives. Unfortunately, today’s early versions of SSDs for laptops also have two big drawbacks when compared with hard drives: They offer much lower capacity and have much higher prices.

For instance, on the newly announced Apple MacBook Air ultrathin laptop, the HDD version costs $1,799 and stores 80 gigabytes. The SSD version costs $2,798, but actually stores less — just 64 gigabytes. On the Toshiba Portege R500 subnotebook, the basic hard-drive version costs $1,999 and stores 120 gigabytes. The cheapest SSD version is $2,699 and also stores just 64 gigabytes.

Despite these limitations, I believe SSDs are likely to become more common and more popular as their capacities increase and their prices drop. Samsung, which makes the 64-gigabyte SSDs in both the Apple and the Toshiba, has already announced an SSD with twice the capacity that costs much less per gigabyte of storage.

I’ve been testing the SSD models of the Portege R500 and the MacBook Air to see how they measure up to their HDD counterparts. My verdict is that the SSD does deliver on its promises, but, in some cases, just barely.

For the small slice of users who are deeply and constantly worried about hard-disk failures, it may be worth it to pay a huge premium today for an SSD that stores less. Because SSDs aren’t subject to mechanical failures, your data are probably safer on them. But for mainstream users, my conclusion is that it’s too early to take the plunge on SSDs, and the best strategy is to wait for prices to drop sharply and for capacity to rise.

In my tests, I focused solely on comparing the hard-drive and SSD models of each machine, which I had had already reviewed in earlier columns. On the same computer, I wondered, would the SSD make a significant difference in speed and in battery life?

To measure battery life, I conducted my usual harsh test, where I turn off all power-saving software, set screen brightness to maximum, turn on the Wi-Fi and play an endless loop of music.

In this test, the SSD made little difference in the MacBook Air and, in fairness, Apple is making no claims of any significant battery-life gains on its SSD model. The SSD MacBook gave me just five more minutes of battery life. Apple says this is because its hard-drive model already uses a very low-power drive.

On the Portege R500, my first battery test with the SSD model actually yielded significantly less battery life than the hard-drive model. The reason: Toshiba ships the base SSD model with a battery with only half of the capacity of the hard-drive model.

When I swapped in the normal battery, which costs $117 extra, the SSD model gave me an added 1 hour and 21 minutes of battery life, about a 36% increase. That extra battery life likely would translate to nearly 2½ hours in more normal usage. It may be worth the huge price premium for some folks.

On both computers, the SSD was faster than the HDD models. The SSD version of the Apple booted up from a cold start, and rebooted with several programs running, about 40% faster. But the gain isn’t as impressive as it seems because even the hard-drive versions of the MacBook Air booted up in under a minute and rebooted in just a little over a minute.

On the Toshiba, which was running Windows XP, the SSD model knocked about 40 seconds off a cold boot time on the HDD version of 2 minutes and 7 seconds. On my reboot test, starting with several programs running, the SSD model was 80 seconds faster. I imagine that on laptops with the slow-booting Windows Vista, the improvements might be more meaningful.

I also tested launching Microsoft Word and Excel, and opening a couple of hefty PDF files on both machines. The SSD versions were faster. But in most cases, the gains were just a few seconds or even fractions of a second.

All in all, the SSD is a promising improvement over the hard drive, but now is not the time for most users to buy it.

Email me at mossberg@wsj.com. Find all my columns and videos online, free, at the new All Things Digital Web site, http://walt.allthingsd.com.

On Jan. 15, Microsoft will be releasing its first new version of Office for the Mac in nearly four years. It is called Office 2008, and it has two big changes from the current version, Office 2004.

For one, it is the first edition of Mac Office designed specifically for the new Intel-based Macs that Apple began rolling out two years ago. While the old Office ran adequately on the new Macs, it was slow to launch and slow to perform certain operations.

Second, the new Mac Office now reads and writes a new set of file formats Microsoft introduced a year ago in the latest Windows version of Office, called Office 2007. Mac owners receiving files in these new formats had been forced to employ separate and clumsy file converter programs.

Now, once again, the Mac version of Office can handle all the same Word, Excel and PowerPoint files — in both old and new formats — created in Windows and vice versa. No translation or conversion is necessary. The files just open and save as they do in the Windows version.

I’ve been testing the new Mac Office on two different Intel-based Macs: an early MacBook Pro laptop and a new iMac desktop. On both machines, Office 2008 launched and ran far more rapidly and smoothly than Office 2004 did.

I also tested Office 2008 with a variety of documents created in the Windows version using the new file formats, which can be identified by four-letter file name extensions that end in the letter “x.” All opened rapidly and perfectly in the new Mac version.

As in the latest Windows version, the new Mac Office 2008 allows you to opt to continue to save automatically all your files in the old, familiar formats-DOC for Word, XLS for Excel and PPT for PowerPoint. But, if you want to switch to the new formats, or need to use a file you receive that was created in them, you can now do so with ease.

Like its predecessors, the new Mac Office differs in one major respect from its Windows cousin: It lacks Outlook, the famed, if bloated, program for handling email, calendar and contacts. Instead, Office 2008 has a new version of Microsoft’s Mac counterpart to Outlook, called Entourage, which performs the same tasks but doesn’t use Outlook’s file format. Like Outlook, Entourage can work with the Microsoft Exchange servers used by corporations, as well as with consumer email systems.

Office 2008 for the Mac has some new features, but it isn’t nearly as radical an overhaul as the latest Windows version was. While the latter junked all the menus and traditional toolbars in Word, Excel and PowerPoint, the new Mac version retains the familiar menus and toolbars. It doesn’t use the so-called Ribbon, a band of icons that is the signature feature of Windows Office 2007.

The new Mac Office, however, does include a new user-interface feature called the Elements Gallery, a narrow strip across the top of the document that lets you easily summon and insert canned features for laying out documents. For example, in Word, you can quickly insert a handsome cover page. In Excel, you can rapidly add a specific type of chart or a spreadsheet preconfigured, for instance, as an invoice. In PowerPoint, you can quickly add customized slide themes and layouts.

There is also a Publishing Layout View in Word that speeds the creation of things like newsletters, and a Ledger Sheet feature in Excel for creating home and small-business budgets.

In my tests, I ran into a few minor glitches. I had to edit my rules for sorting email in Entourage to get them to work and, at first, I was unable to add new spellings to my custom dictionary in Word, though that problem went away. But, generally, the program worked well.

The standard edition of the new Office costs $400, or $240 to upgrade your current version. There is a deluxe edition, which includes a professional media-management program, for $500, or an upgrade price of $300.

For most average users, however, I recommend the Home and Student edition for just $150 that can be legally installed on up to three different Macs. This inexpensive edition has full versions of Word, Excel, PowerPoint and Entourage, but doesn’t work with Exchange servers.

Microsoft is also running a sale, through Jan. 14, under which anyone buying Office 2004 gets a coupon that allows them to receive the high-end version of Office 2008 for just a shipping and handling fee of $6.99.

Microsoft Office 2008 for the Mac is a solid program that I can recommend for anyone with a new Mac. It’s not revolutionary, but it does the job.

Email me at mossberg@wsj.com. Find all my columns and videos online, free, at the new All Things Digital Web site, http://walt.allthingsd.com.

But in recent weeks, I’ve been bombarded by reader emails asking for Mac-buying advice. So, here’s a quick guide — a sort of Mac FAQ — to shopping for a Macintosh. As with my Windows guides, this is aimed at average, mainstream users doing typical tasks, not techies or businesses or hobbyists.

Q. Who should consider a Mac?

A. Pretty much every average consumer using a computer should at least look at the Mac. It combines gorgeous hardware with an operating system I consider superior to Windows, with better built-in software. It can even run Windows programs if you buy and install a copy of Windows. And unless you do that, you won’t be vulnerable to the vast array of viruses and spyware that threaten Windows users. Only a handful, so far, have been written to run on the Mac operating system, OS X.

Q. Who shouldn’t consider the Mac?

A. People who spend much of their time playing cutting-edge games should stick to Windows computers, because there are far fewer games written for OS X. Apple doesn’t offer hardware tuned for serious gaming. People looking for the lowest-price PCs should also avoid the Mac, because Apple’s cheapest model, the Mac Mini, costs $599.

Another group that should shun Apple’s computers are people who depend for support on corporate IT departments that are either ignorant about, or hostile to, the Mac. Finally, if you know and like Windows, and expect mainly to use Windows programs, stick with a Windows PC.

Q. Can I run Microsoft Office on a Mac?

A. Yes. Microsoft makes a Mac version of Office, which uses the same file formats that Word, Excel and PowerPoint for Windows have used for years. A new version of Office for the Mac is due in January and it will handle the new file formats Microsoft introduced this year. But the Mac version of Office omits Outlook. It has a similar program called Entourage, but Entourage can’t use Outlook data files. If you want a Mac but must have Outlook, you will have to install Windows.

Q. Can I use all my Windows files on a Mac?

A. Out of the box, Macs can handle all the common file types Windows machines create, including text files, pictures, songs and Adobe PDF files. The Mac even comes with a simple word processor that can open Microsoft Word files.

However, some specialized Windows programs create files that the Mac can’t handle out of the box. And the Mac version of Quicken has a difficult time properly handling Windows Quicken files. If you are a Quicken fan, install Windows and run the Windows version.

Q. Can I mix Macs and Windows on the same home network?

A. Macs can plug and play with most brand-name wired and wireless routers, and can share Internet connections with Windows PCs.

Q. How are Macs at Web surfing?

A. Fine. Apple’s built-in Safari browser is very good and the Mac version of Firefox is essentially identical to the Windows version. However, Macs lack an up-to-date version of Microsoft’s Internet Explorer, so you will have to install Windows if you need IE.

Q. Can Macs run standard peripheral hardware?

A. Macs can run nearly all keyboards, mice and printers that use USB connections, even ones that don’t explicitly say they run on Macs.

Q. What desktops does Apple offer for consumers?

A. Apple’s main consumer desktop is the one-piece iMac, which I regard as the best consumer desktop on the market. It comes in four models, with built-in 20-inch or 24-inch, flat-panel screens at starting prices ranging from $1,199 to $2,299.

Q. How about Mac laptops?

A. There are two. The entry-level MacBook has a 13-inch screen and a starting price of $1,099. The high-end MacBook Pro comes with either a 15-inch or 17-inch screen and starts at $1,999. Apple currently doesn’t offer a smaller laptop for road warriors, but there are persistent rumors that it will do so soon.

Q. What minimum specs should I look for on a Mac?

A. All Macs come with at least one gigabyte of memory — twice the minimum required for the new version of OS X, called Leopard. If you can, get two gigabytes. Apple charges a lot for extra memory, but you can buy it for less at stores and online providers.

Macs use the same dual-core Intel processors and graphics systems as many mainstream Windows computers; and, as with Windows, I wouldn’t pay extra for greater processor speed.

The iMac comes with at least a 250-gigabyte hard disk, and Mac laptop hard disks start at 80 gigabytes. Mainstream Windows desktops typically start with larger hard disks. But Apple offers much larger disks as options, which you should consider if you store a lot of photos, music and video files.

Email me at mossberg@wsj.com. Find all my columns and videos online free at the new All Things Digital Web site, http://walt.allthingsd.com.

There are several reasons for this, including the security problems in the dominant Windows platform from Microsoft; spillover from Apple’s blistering success with its iPod music players; the fact that Macs can now run Windows programs; and Apple’s highly successful chain of company-owned retail stores.

But another key factor has been the Mac operating system, called OS X, which came out in 2001. It has proved to be as powerful and versatile for mainstream consumers as Windows, yet easier to use and more secure. And Apple has upgraded OS X far more rapidly than Microsoft Inc. has upgraded Windows, bringing out major new releases roughly every 18 months, while Microsoft struggled for more than five years to produce the latest Windows iteration, Vista, which came out in January.

On Friday evening, Apple will release yet another new version of OS X, called Leopard, to replace the current version, known as Tiger. I’ve been testing Leopard, and while it is an evolutionary, not a revolutionary, release, I believe it builds on Apple’s quality advantage over Windows. In my view, Leopard is better and faster than Vista, with a set of new features that make Macs even easier to use.

Leopard will come preinstalled on all new Macs. It can also be purchased for $129 as an upgrade to existing Macs that, depending on configuration, can be as many as six years old. Unlike Vista, which is sold in four noncorporate upgrade versions ranging from a $100 stripped-down “basic” edition to a $259 deluxe “ultimate” edition, there’s only one version of Leopard. It includes all the features, from those aimed at novices to those aimed at power users.

For me, the marquee features in Leopard are a new function called Time Machine that automatically backs up your entire computer in the background; two new methods, called Cover Flow and Quick Look, for rapidly viewing the contents of files without opening any programs; and new techniques that allow you to access the files in, and to remotely control, other computers on your network or connected over the Internet with a few clicks and no technical expertise.

Plus, Apple’s free software for running Windows on a Mac, called Boot Camp, which was formerly an add-on users had to download and install, is now built right into the operating system. And, in my tests, the third-party Fusion program for running Windows and Mac programs simultaneously continued to work fine in Leopard.

I did notice a few drawbacks, but they were minor. The menu bar is now translucent, which can make it hard to see the items it contains if your desktop picture has dark areas at the top. The new folder icons are dull and flat and less attractive than Vista’s or their predecessors on the Mac. While Time Machine can perform backups over a network, the backup destination can only be a hard disk connected to a Mac running Leopard. And, on the Web, I ran into one site where the fonts on part of the page were illegible, a problem Apple says is known and rare and that I expect it will fix.

While Apple claims the new system includes more than 300 new features, there is nothing on the list that could be considered startling or a major breakthrough. Some of Leopard’s features are unique, but many others — such as backing up data and quickly viewing files — have been available on both Windows and the Mac via third-party programs or hard-to-find geeky methods buried in the operating systems. Leopard has made them easy to find and use.

When I upgraded my personal iMac desktop to Leopard, it took less than an hour, and after the process was complete, all my programs, including the Mac version of Microsoft Office, the Firefox Web browser and Adobe Reader, worked rapidly and fine. I was still able to run Windows XP via Fusion. And my previous installation of Boot Camp, which turns the iMac into a speedy, full-fledged Vista machine after a reboot, worked perfectly. All my Vista programs and files continued to function properly.

With Cover Flow, users get a visual preview of a computer’s files without having to open programs.

In fact, every piece of software and hardware I tried on two Leopard-equipped Macs — a loaned laptop from Apple and my own upgraded iMac — worked fine, exhibiting none of the compatibility problems that continue to plague Vista. My old Hewlett-Packard inkjet printer, for which Vista lacks the proper software, worked instantly in Leopard, even over the network. And, unlike with Vista, it was able to print on both sides of the page. I popped my old Verizon cellphone modem card into the test Leopard laptop and it worked, too, with no software installation or tweaking.

Leopard felt about as fast as Tiger, and it started up much faster than Vista in my tests. I compared a MacBook Pro laptop with Leopard preinstalled to a Sony Vaio laptop with Vista preinstalled. Even though I had cleared out all of the useless trial software Sony had placed on the Vaio, it still started up painfully slowly compared with the Leopard laptop.

It took the Vista machine nearly two minutes to perform a cold start and be ready to run, including connecting to my wireless network. The Leopard laptop was up, running and connected to the network in 38 seconds. In a test of restarting the two laptops after they had been running an email program, a Web browser and a word processor, the Sony with Vista took three minutes and 29 seconds, while the Apple running Leopard took one minute and five seconds.

Here’s a rundown of some of Leopard’s key features. Much more detailed information is available at apple.com/macosx.

File management: Apple’s Finder, the equivalent of Explorer in Windows, now offers two new ways to quickly see what your files contain. You can still view them as icons or lists. But you can also use Cover Flow, the same system Apple uses in iTunes and on the iPhone to display album covers for music. In Leopard, a large preview of each file you select appears above the list of files in a folder, and you can rapidly scroll through these icons. These previews are live, and their contents can be viewed without opening the program that is normally needed to display them.

Time Machine backs up files.

For instance, if the file is a video, you can just click on it, and it will play. If it’s a multipage PDF file, you can click on it, and arrows will appear allowing you to flip through the pages.

An even better and deeper look can be obtained using a feature called Quick Look. Just hit the space bar or click on a toolbar icon, and a preview of any selected file zooms out. You can even view multiple sheets in an Excel file via Quick Look without launching Excel.

Another quick new way to see your files is available in the Dock, the Mac’s equivalent of the Windows Task Bar. Here, any folder you place on the right side of the dock will display its contents, after a single click, either as a grid of icons displaying miniversions of the file or as a “fan,” or arc, of such icons. These special Dock folders are called “Stacks.” Leopard includes one by default that is the destination for everything you download from the Internet, so your desktop will no longer get cluttered with downloads,

Time Machine: This built-in feature will continuously back up all of the contents of your Mac to either an external hard drive directly connected to the computer, or to a hard disk connected to another Mac running Leopard that’s on your network. The initial backup, in my tests, took all night, but after that, the system updates the backups hourly and I didn’t notice any slowdown during the process.

To recover any file you deleted, you simply click on the Time Machine icon, and you are taken to a view that shows file folders — or your email or address book or photo collection — in a stack of windows that appear to go on infinitely. You click on an arrow and the stack of windows zooms until you arrive at the last view in which the missing file existed. Then, you click “restore,” and the file is recovered in your normal desktop view. You can also restore whole folders, groups of files, or even an entire hard disk.

Shared computers: In Leopard, any computer that has been set to be shared on your network shows up on the left side of every Finder window. Click on it, and you can access whatever folders have been shared on those machines. Depending on the remote computer’s security settings, you may first have to enter a user name and password. It’s the simplest method I’ve ever seen for accessing other computers on a network. And it works with Windows PCs as well as Macs. When I first turned on the Leopard laptop in my office, it immediately found a shared folder on my colleague’s old Dell running Windows XP. She hadn’t even remembered sharing the folder, which contained files from 2003.

You can copy or move files to and from these shared computers, or view their contents with Cover Flow and Quick Look, or open them in programs on your own computer.

If you are a member of Apple’s optional .Mac service, which costs $100 a year, you can use a feature called “Back to My Mac,” which can access your Macs from thousands of miles away over the Internet. However, this feature works only over certain kinds of routers (not all of them Apple’s) and, as my router didn’t qualify, I couldn’t test it.

Remote control: For any Mac in your shared-computers list for which you have permission, you can take over the screen by simply clicking on a button called “Share Screen.” You can also remotely control distant Macs over the Internet using Apple’s built-in iChat instant messaging program, as long as you have permission and the Macs are running Leopard.

Stacks displays the files in folders in the dock.

iChat: Apple now allows you to use its instant messaging program with Google Talk as well as AOL’s AIM service, and you can set up a video chat in which you can present a slide show or display a document. You can also add special backgrounds that can make it look as though you’re someplace else, like Paris. In my tests, this even worked with someone on the other end using a Windows XP computer running the latest version of AIM.

Spaces: In order to cut down desktop clutter, Leopard lets you set up as many as 16 different desktops that can run simultaneously, with different programs open in each. You switch among these desktops by using keyboard commands or a menu.

For instance, you might have your iPhoto and iTunes running in one “space,” or desktop, your Web browser and email program in another, and Windows XP in another.

Leopard isn’t a must-have for current Mac owners, but it adds a lot of value. For new Mac buyers, it makes switching even more attractive.

Email me at mossberg@wsj.com. Find all my columns and videos online free at the new All Things Digital web site, http://walt.allthingsd.com.

And yet, last week, Apple brought out a new spreadsheet program called Numbers, thus completing one of its least-known products: a productivity suite called iWork. The iWork ‘08 suite, which competes with the Macintosh version of Microsoft Office, also includes a word-processing program called Pages and a presentation program called Keynote. The two were upgraded last week. IWork costs $79, about half the price of the lowest-cost version of Microsoft Office, which sells for $149.

In the past 10 years, Apple has out-designed Microsoft and its hardware partners in a number of key areas. But can Apple really take on Microsoft in the category of productivity software, where Office rules on both Windows and the Mac? To find out, I’ve been testing the new iWork, which runs only on the Mac, against the Mac version of Office.

My verdict: iWork ‘08 is a nice product, capable of turning out sophisticated and attractive word-processing, presentation and spreadsheet documents. It can even read Microsoft Office documents, whether created on the Mac or on Windows computers, and can save documents in Microsoft Office formats so they can be opened in Office on the Mac or on Windows.

But iWork simply isn’t as powerful or versatile as Microsoft Office, especially when it comes to word processing and spreadsheets. And it suffers from a design that places far more emphasis on making documents look beautiful than on the nuts and bolts of the actual process of writing and number-crunching.

There’s one big omission in iWork: It has no integrated email, contacts and calendar module comparable to Outlook in Windows or to Entourage, the Outlook equivalent that’s a part of the Mac version of Microsoft Office. Apple decided to rely on the very good email, calendar and address book programs that it builds into every Mac.

But iWork has one big plus: It’s the first Mac office suite that can open (though not create) files in the new formats Microsoft introduced in the Windows version of Office earlier this year. The Mac version of Office won’t do that until Office 2008 is out in January.

The new Numbers spreadsheet has some refreshing innovation that makes it far more approachable for casual spreadsheet users than Microsoft Excel often is. Numbers allows you to place multiple spreadsheet tables, plus charts and graphics, on a blank canvas that you can arrange any way you want. Each of the spreadsheet tables functions like an Excel spreadsheet with individual cells able to hold numbers, text or formulas.

Numbers has some other nice features to make things simpler. Any cell meant to contain a value you type in can be controlled with a slider or up-and-down arrows, so you can rapidly see how different numeric values would alter calculations without a lot of retyping.

I also found that Numbers made it easier than Excel to sort columns, and to add or move columns and rows. It’s also easier to create formulas using the actual names of columns and rows rather than their number/letter coordinates. And Numbers lets you drag and drop common formulas, such as Sum and Average, to the bottom of a column of numbers.

For real spreadsheet jockeys, however, Numbers is wimpier than Excel. It has only about half as many functions for making calculations and doesn’t do pivot tables.

The Pages program was originally more of a page-layout program than a writing tool. The new version attempts to fix this imbalance with a less artsy word-processing mode. But the effort is only partly successful. It still de-emphasizes some writer-friendly features. For instance, its auto-correct function is much weaker than Word’s. Another example: In Word, to see how many words your document contains, you just glance at the bottom of the screen. In Pages, you must dig down into a submenu to find the answer. The command for showing invisible formatting marks also is harder to find than in Word.

The strongest part of iWork is Keynote, the presentation program, which still makes it easier than Microsoft’s PowerPoint does to make rich, beautiful slide shows. The new version isn’t a major overhaul, but it includes a new feature called Instant Alpha that makes it easy to eliminate unwanted backgrounds from photos.

In my tests, importing and exporting documents between iWork and Office worked fine for simple files. But fidelity isn’t always perfect, especially in Numbers, where missing Excel functions or Numbers-only features don’t carry over.

If you’re a Mac user with basic word-processing and spreadsheet needs, and a strong emphasis on design, iWork is good choice, especially if perfect compatibility with Microsoft Office isn’t a high priority. But for office-suite users more concerned with function than form, I’d recommend sticking with Office.

Email me at mossberg@wsj.com. Find all my columns and videos online free at the new All Things Digital Web site, http://walt.allthingsd.com.

All of the familiar Office toolbars and menus have been replaced by the Ribbon, a super toolbar divided into seven tabs grouped by commands.

So, when Microsoft makes significant changes to Office, it’s a big deal. And the latest version of the software suite, called Office 2007, due out Jan. 30, is a radical revision, the most dramatic overhaul in a decade or more.

I don’t use the word “radical” lightly. The entire user interface, the way you do things in these familiar old programs, has been thrown out and replaced with something new. In Word, Excel and PowerPoint, all of the menus are gone — every one. None of the familiar toolbars have survived, either. In their place is a wide, tabbed band of icons at the top of the screen called the Ribbon. And there is no option to go back to the classic interface.

In Outlook, the Ribbon hasn’t kicked out the menus and toolbars in the program’s main screens, but if you compose an email, or set up a new contact or appointment, you’ll see it.

As if this weren’t enough, Microsoft has also changed the standard file format for Office files. Older versions of Office, on both Windows and Macintosh computers, won’t be able to read these new file types without special conversion software. The new version can, however, read files created in the older versions, on both Windows and Mac, without any conversion software.

These changes in Office, while much less publicized, are far bolder and more important than the mostly cosmetic user interface changes in the highly hyped new version of Windows, called Vista, which comes out on the same day.

After months of working with the Ribbon and other new features of Office, I believe they are an improvement. They replace years of confusing accretions with a logical layout of commands and functions. They add easy and elegant new options for making documents look good. And they make it much simpler to find many of the 1,500 commands that Office offers, but had buried in the past.

In the new Word, above, the round Office button replaces the file menu in the old Word, below, which had commands spread across many menus and toolbars. New features include contextual spell checking and translations into other languages.

So, Microsoft deserves credit for being bold and creative in designing Office 2007. It has taken a good product and made it better and fresher.

But there is a big downside to this gutsy redesign: It requires a steep learning curve that many people might rather avoid. In my own tests, I was cursing the program for weeks because I couldn’t find familiar functions and commands, even though Microsoft provides lots of help and guidance.

It’s as if Toyota decided to switch the position of choices on the automobile shift lever, or Motorola decided to rearrange the buttons on the cellphone key pad. Even if the companies could conclusively show that the changes made life easier, many people would be annoyed at best, and furious at worst.

In the case of the new Office, I think the changes are most beneficial for users concerned with the layout and design of documents. The commands that are now better arranged and easier to find are mainly those that relate to formatting, layout, graphics and design.

By contrast, basic composition and editing are aided by the new design either very little or not at all. If you mostly compose plain Word documents, simple presentations and plain spreadsheets, the new design may not be worth the effort to master it, and you might want to stick with an older version of Office. People with the new version will still be able to read your documents and you can get free conversion software so you can read new files.

The old Word.

The other group of users who might be better off skipping Office 2007 are power users who know many commands and have customized their menus and toolbars heavily. The new Office is much less customizable.

In fact, you can’t customize the Ribbon. To add favorite commands, all you can do is customize a tiny minitoolbar in the upper left corner of the screen, called the Quick Access Toolbar.

For people who mostly control Office via keyboard commands, and rarely use menus and toolbars, all of the basic keyboard commands are the same.

There are other nice additions. In Word, Outlook and PowerPoint, there is now contextual spell checking, which points to a wrong word, even if the spelling is in the dictionary. For example, if you type “their” instead of “they’re,” Office catches the mistake. It really works.

In addition, throughout Office, there is a function that translates a word or sentence into other languages. In PowerPoint and Excel, there are new, better-looking graphics for charts and tables.

And all the programs have Live Preview, a feature long offered by WordPerfect, which shows a formatting change before you commit to it. You can see what a new font or style would look like by hovering over the choice with the mouse.

Outlook, the least changed of the programs, finally catches up to other email programs with a fast search capability and the ability to preview attachments without opening them.

But the Ribbon is the biggest change. It’s essentially a super toolbar divided into seven logical tabs, which attempt to group similar commands. Each tab brings up a new version of the Ribbon. Common file-handling functions like Open, Save and Print aren’t on the Ribbon. They are accessed by clicking on a big round icon at the upper left called the Office Button, which is roughly the equivalent of the old File menu. Clicking the Office Button also displays a much larger and longer list of recently opened files than the old File menu did, and you can even permanently “pin” files to this list.

There’s no doubt that some functions are quicker and easier in the new interface. Narrowing the margins in a Word document now takes as few as three clicks, compared with up to 14 clicks and keystrokes in old versions.

Applying styles to a Word document is also easier. The Ribbon has a bunch of them in the Home tab, illustrated with big square icons that show what they look like, and you just can just click and apply the one you want.

But some less-common tasks are harder without the old menus and tool bars, such as adding a new word to the Auto Correct system.

Like a lot of things in Office over the years, the new file formats have been instituted mainly to aid big corporations and organizations. For consumers and small businesses, the main benefit of the new formats is to shrink file sizes, but that benefit is likely to be far outweighed by the hassles and incompatibilities they introduce.

Luckily, you can set up Office 2007 to ignore the new formats and save your files in the old formats to be read without conversion software. But some new formatting features may not be usable in the old formats.

Free conversion software is available now at office.microsoft.com. Click on the Downloads tab and select Microsoft Office File Formats Compatibility Pack.

Mac Office users will have to wait until later in the year for Microsoft to release converters that will allow their version of Office to read the new file formats. But a third-party conversion program, for Word files only, has already been released. It’s called docXConverter, and can be downloaded at www.panergy-software.com for $20.

In another move that will likely annoy many consumers, Microsoft has stripped Outlook from the low-price home version of Office. This version, which costs $150 and can be used on up to three computers, was formerly called Student and Teacher edition, and now has been renamed Home and Student. Formerly, you were supposed to have either a student or a teacher in your household to buy it, though stores never checked this. Now, that pretense has been dropped.

But this edition of Office has been made less valuable for many folks. It still includes Word, Excel and PowerPoint, but now, instead of Outlook, it has OneNote, a very nice program for creating and organizing notes and other research materials. Many home users would prefer Outlook. But to get Outlook in Office 2007, you either have to buy Office Standard for $399, or buy a standalone version of Outlook for $109.

If you’d like to get more out of Office, especially in the area of how your documents look, Office 2007 is a big step forward, and worth the steep learning curve it imposes. If you’re happy with Office now, or you mostly create plain documents where formatting and design aren’t high priorities, it may not be worth the effort to buy and learn the new version.

Email me at mossberg@wsj.com.