I run my Mac because when I started out, the Ataris were too slow, and the PC's simply couldn't be trusted. Macs worked, that's why I got a Mac! I've never found a reason to change ever since, and to change would mean changing all my software and hardware. I just don't think so.
Interesting anecdote: A few years ago, the biggest music store here were dealing both Macs and PC's. However, they decided to quit dealing with PC's, because all the PC customers needed so much support that the store realized they would have to hire a guy on full time, solely to deal with that. They simply thought they couldn't afford to go on with the PC's.
Well, like I said this was a few years ago, and from what I understand Microsoft have finally gotten a grip. So if I started out today, it may have been a whole different story.
Cheers
/Henrik