I bought a power color GF2 mx400 a couple years ago. I ran it mostly 24/7 for quite a while - then I sold it to my sister. She's still using it with no problem. As far as driver support - there's no special features, so it seems they just use the standard NVidia (or ATI) reference drivers. I will say that the cooling fan has held up much better than the Abit and Visiontek cards I've had.
As far as tech support - I haven't needed it, but their web site is very sparse. The older cards are no longer listed there. And according to their site, they charge $20 "shipping & handling" to RMA a card
Overall - if you're just getting a cheap card, PowerColor is probably OK, but if you're spending big bucks for a high end card, I'd stick with the name brand for better support and RMA service.