I got this powerbook a few months ago because my bookstore offered a discount after the macbook pros came out. I guess they wanted to get rid of their powerbooks..
This thing is portable! In the sense that it has a small footprint, anyway. You probably heard from a lot of people that it's heavier than it looks, and it's true. But, I carry this thing in my backpack and I feel like there's nothing in my backpack at all.
The screen is probably the most important part of the laptop for me. Too small + high resolution = eyes hurt. Too big + high resolution = not portable. This is a personal opinion, but XGA just seems too small for me. But for the 12" powerbook, I decided that XGA would be okay because I could just hook it up to an external CRT at home.
The quality of the screen, ehh. It's not good. I'm spoiled by my Inspiron 700m. If you get a chance to go to an Apple Store, look at the screen! It may not look bad for the first few minutes, but after a while, it'll look bad. If you've never used those extra bright screens before, the powerbook's screen may not look that bad to you.
For just web browsing, the battery life is about 4.5 hours. But, I edit source code files a lot and do source code commits, which means lots of hard drive work. Working on files, usually I get a little under 4 hours.
If you use secure shell, expect battery life to drop even more, especially when using wifi + X11. The battery life will drop to 3.5 hours.
This is considered good battery life =P But its not as good as those crazy ultra low voltages at 7 hours =/.
OS X for everyday tasks:
ITUNES!! I never was able to run Itunes on Gentoo. Everything usb pluggable just works. Support for external LCD/CRT, just plug it in and it works. Digital Camera, just works =P. No configuration at all. Even the printer just worked.
I guess this is the same as in Windows, where everything plugged in usually works. Sometimes you'll have to install a driver, sometimes you won't.
OS X as a programming environment:
This is where Linux and Unix command line really shine.
OS X provides a lot of the tools either natively or in their CD which they include in the package. What this means is, just pop in the CD, and you get everything. Usually though, you can just download all of the tools from the internet, Gentoo uses portage and Windows has cygwin. I guess OS X has very very little configuration, just pop in the CD! Gentoo also has very little configuration, just emerge =P. Whereas Windows has cygwin.... eh.
The only thing I had trouble with was gvim. To get it, just install Darwin Ports (Google it!) and run port install vim +aqua +(ruby|python|whatever extensions you need). Also, OS X 10.4 has a problem with the command 'curl'. CURL IS NEEDED FOR DARWIN PORTS. If you do not do a system update before you run a port install, some port installs will not work. (found that out the hard way).
If you're used to doing work in a *nix environment, you'll feel right at home with OS X. Any command line programs you need, you can usually find through Darwin Ports (like wget) if OS X doesn't provide it. Some stuff provided either natively or in the CD are: most of your Unix tools including gcc, Makefile, gdb, even javac is included, javadoc, ruby, python, perl, vim, emacs. What suprised me though was Apache was included.
Some software I recommend downloading that's not included: CocoaMySQL for MySQL users, Darwin Ports, and Fink. With Darwin Ports and Fink, you can get any *nix tool you need.
In summary, screen isn't that great, it's heavy but small, and it has a decent battery life. If you can afford it, try it out. It's like Linux without the configuration and support for external hardware. It's like Windows with a bettery command line and more support for unix tools. And it has a pretty GUI.