I spent a couple of days working completely on battery power while preparing for this review. While I did reduce the screen brightness and take advantage of some other Energy Saver features available in all Mac laptops (such as allowing the hard drive to spin down and the screen to dim when not in use), I didn't go overboard. I kept the screen at about two-thirds of full brightness, for example.
When I stuck with word processing, Internet access and occasional tasks in Adobe CS3, battery life averaged between 2 hours 40 minutes and just over 3 hours. Using older PowerPC applications on occasion -- those not compiled to run natively on Intel processors -- seemed to cut down battery life by at least a few minutes. As you would expect, using disk- and media-intensive applications also pulled down overall battery life.
I wouldn't call this MacBook Pro a power hog by any means. It is certainly on par or a little bit better than most laptops from Apple or other manufacturers. But I also wouldn't venture on a cross-country flight without a power adapter. (Apple offers an adapter that can be used on airplanes for US$49 to ensure access to any in-flight power outlets available.) Likewise, I'm not sure I'd rely solely on battery power for a full afternoon of video or audio editing, intense gaming or doing anything beyond some basic word processing with the screen brightness turned way down.
Without a doubt, the 17-in. MacBook Pro is an impressive machine, both in terms of performance and the new LED screen. It has certainly changed my perception of Apple's largest laptop. Like the MacBook Air at the opposite end of the spectrum, it shows that Apple understands there isn't a one-size fits-all machine for Mac users on the go.
If you are someone who works with video, graphics or music for a living and you need a portable workspace, then you have to check out this laptop. Even if media work is something you only do as a hobby or if you're just eyeing a portable with an amazing display for movies or games, this machine is well worth a look. You may decide that it's still bigger than you need. Or you may find, as I did, that your assumptions about size and weight pale in comparison to the solid design, stunning screen and ample processing power available on Apple's biggest laptop.