Well personally i prefer the PC but if your happy with the Mac i see no reason for you to change over at this point.
I'm sure there will be lots of Mac and PC users in here exalting the virtues of both systems but at the end of the day its hard enough to learn Maya without at the same time having to move into an OS environment your not comfortable with.
David 
From a readers' Q and A column in TV GUIDE: "If we get involved in a nuclear war, would the electromagnetic pulses from exploding bombs damage my videotapes?"