I'm primarily a PC guy, but I've used Macs over the years. My latest addition is an iMac with a 20 inch monitor and built in hardware. It's a piece of art as much as hardware. I miss the 747-like CPU fan on my PC like a rash. Here's a quick summary after two weeks of how things stack up, on one view:
To the Mac:
1) Style - it's not just a meritocracy - remember Jaguar?
2) Hardware integration - nothing to think about - nothing.
3) Music and video editing - brillant built in applications and hardware integration
4) Shell access - it's Linux
5) User interface - a slight edge here
6) Performance - partly to do with less software availability, but generally true
7) Form factor - I now live with less noise, wires, plugs, etc.
To the Vista PC:
1) Software - there's lots more of it
2) Programming - you're boxed in to web apps, Objective C, or sometimes updated Java on the Mac
3) Office - it doesn't compare on the Mac
4) Reliability
I don't think there's anything remarkable here, expect #4, and I'd say that's the the primary reason I won't start buying iMacs for the office. I've "Forced Quit" too many times over the past few weeks for my liking. I think there is a misperception that apps written for OS X are more stable, but I'd say, anecdotally, that this is not true. Among the crashers: mail, XCode, and Firefox. I believe I managed to crash the OS as well. (Grey screen, giant apple, hardware unresponsive)