i am a mac user for about an year. IMHO opinion it worths
spending extra cash for it. the thing i like the most about os x is that i never turn off the system just putting it to "sleep" and it works like a charm. do that with a windows based laptop and see what happens (my boss did it and it crashed 3 times of 5).
the things i use it for are: system administration via iTerm (great terminal emulator
) and a desktop computer mostly, being the only "personal computer" i have it runs 14 to 18 hours a days and never had problems with it's stability and/or performance, although it gets warm after 4 hours or so but still stable.
i have never been much into X setup and almost always i have chose preconfigured OS's like: Ubuntu (which at some point just crashed, doesn't want to mount /proc) pc-bsd (which i use it at work on my desktop - i am very pleased with it).
mac is one of the things that "just work" from a desktop stand point.
my 2 cents
/v