First and foremost, Mac OS X is way more stable than PC. For me, I'm using a Macbook Pro 15" 2011 (8,2). From my point of view, I have yet to encounter a non-responding app (perhaps because i've got 2.3Ghz i7 and 8GB 1333Mhz DDR3 RAM, but I'm not too sure about lower end models).
Windows crashes on you, but Mac doesn't.
It has to be said that graphics is way better.
And if you ever get stuck and want to use a Windows-only app, you can either shell out 65 quid or 80 bucks for parallels 6 or VMware (which is similar)
Or either use BootCamp (free but a little troublesome in setting up) for the best results. BootCamp is built-into Mac.