I've had the "pleasure" to use Mac OS X a few times and compaired to, for instance GNOME it just sucks. A few points:

• the dock: I close windows, they stay active in the dock? Why!?
• apple+tab: only switches between different window classes. Ever had two Iterms open? Good luck. (Yes, I know, you should then use a different key-combination. Why!?)
• resizing: the mouse pointers doesn't change. I really like the little hand I get in gnome when I move windows.
• finder: new window -> Applications -> Firefox. What's wrong with a simple (start)menu?
• placement of the cntlr key: this is soo annoying.

Another point in case: valhenson.livejournal.com/11711.html You cannot enable follow-focus-mouse.

The only cool thing is that resume/suspend just works and that the wireless is flawlessly detected. This is also the only reason I don't have Linux running on it...

My point being: this is a Mac with supposedly the best GUI ever. Well not in my book...