I'm running Maya 5 on a PC at home, and the same version on a Mac for my classes. As long as you have a 3 button mouse for your mac there is generally no difference in how the two systems operate. As was mentioned before, what it really comes down to is price. I've been able to build a brand new dual 2.4Ghz Xeon system for about $2000 CND, that's about $1500 USD. Compare that with the price of a 2Ghz dual G5, i think it's about $3000+ USD. So going the PC route, even with workstation-calibre parts is still only about half the price and the same level of performance.