PC vs Mac is like Ford vs Chevy to each is own.
I've worked on both, they both have there strong and weak points.
One note though, I use a PC with Pro Tools ( Digi001 ) which is a Mac based program. My PC is custom built and has only crashed on me once in almost a year. People run into problems with PC's when they get a Dell, or gateway, or Compaq and then try to run audio programs on those machines. Motherboards, what chip set its using, determine alot people need to learn about those things before they get in over there heads. I did and it made the difference between no problems and a nightmare and I've heard and read about a million of those stories.
Bottem line learn everything you can about everything that is running in your studio, so if there is a problem you can solve it.