The thing is ATI cards are better when it comes to the hardware part, but when it comes to drivers they suck, I once had a Radeon where Maya crashed all the time, turned out that de catalyst driver had a thing called triple buffering which made Maya crash.
I then had a Quadro FX 4600 which worked fine and now I have a Geforce 580 which works great.
I believe in all honesty that the differences aren't that great anymore between Quadro's and GEForce cards, in some cases the GeForce outperforms a Quadro.

But as others said it is something you need to look into for yourself