Mac users walking on Air

Let’s concede the first and most important point: The $1,799 MacBook Air from Apple Inc. is really thin and really light. At its thickest, the computer is 0.76 inches, slimming down to an amazing 0.16 inches. It weighs only 3 pounds, and that’s less than half the heft of the 17-inch MacBook Pro that’s in my office.

If you travel frequently, or if you have any care for your shoulders and back, the MacBook Air is as close to a must-have as any computer can be.

This was most plainly evident when I wandered the halls of a convention in Nashville, Tenn., toting the MacBook Air in a briefcase. The computer itself was almost negligible in terms of its presence: I didn’t really feel it in the bag. Yet, when I needed to check e-mail or do some writing, the power of the MacBook Air was there, ready to respond in an instant.

As you might imagine, there are trade-offs for any “downsizing” of a notebook computer, and the MacBook Air, announced in January, is no exception. Most obvious among the “omissions” is the lack of a disk drive: You can get an external one for $99 extra. The built-in speaker is mono; if you want to have stereo sound, headphones are required.

You can connect the computer to an ethernet network, but it will require a $29 adapter and the “sacrifice” of the computer’s one and only USB port. The battery is not user-accessible; Apple stores can replace a worn-out battery for you. There’s no express card slot for add-ins such as a broadband wireless card.

Those are the negatives, if you elect to view them as such.

On the plus side, the MacBook Air’s built-in 802.11n wireless networking, the top level of Wi-Fi at present, is available, as is the latest version of Bluetooth. At my hotel, the Wi-Fi worked quite well. At the trade show, I used a Sierra Wireless broadband adapter and AT&T;’s 3G data network with good results, even deep within the Gaylord Opryland Convention Center.

In operation, the MacBook Air performs as well as any portable Mac I have used. It comes with 2 gigabytes of RAM; no more can be added. The $1,799 model ships with an 80 gigabyte hard disk drive. Add $1,299 to the price tag, and you get a MacBook Air with a “solid state,” or flash-memory chip, 64 gigabyte hard drive, the advantage being no moving parts in the hard drive.

The 13.3-inch (diagonal measure) LCD display is quite nice, as is the full-sized, backlit keyboard. The MacBook Air’s trackpad incorporates new technology that lets users employ “pinch,” “swipe” and “rotate” gestures to perform various tasks. It takes a bit of learning, but the end result is rather pleasant.

The lack of an optical drive made things a bit challenging at the start of my evaluation. Apple has revised its “Migration Assistant” program to handle transfers from an old Mac to a new one via Wi-Fi, but I wasn’t thrilled with the estimate of a 19-hour transfer process.

Instead, I opted to use a Time Machine backup of my old system and restore those files to the new unit. All went well, I’m happy to say.

Apple later told me users could create an ad hoc ethernet link for such transfers.

I’m jazzed about the MacBook Air, but will do some more testing of its newer features, such as the one that lets you use another computer’s optical drive, via Wi-Fi, as your own. The results, and more analysis, will appear here shortly.

• Read Mark Kellner’s Tech Blog.