physx7 :
I heard that ATI has more driver problems than Nvidia and that ATI cards also use more power. Is that true?
It's funny you've got old and new beliefs mixed together.
For the drivers, they're tied, if anyting ATi woud've had the lead, but even that's for issue that don't affect gamers. Overall they're basically tied.
For power however the ATi's are in general more power hungry right now, but that wasn't always the case either. When ATi's drivers were considered bad, their power useage was much lower than nV, now the roles are reversing.
The drivers are a non-issue nowadays, but for the power situation it's good to read reviews like those at XBitLabs and see where the card you're considering falls.
And like alot of factors, power isn't the only thing, but if you're going to be trying to build on an existing rig it's a very important thing, so it's definitely worth considering, and of the ones above the GF7950GT is more powerful in most situation (games like Crysis are an unknown, but it does OK in Oblivoin compared to the other GF7s and holds it's own unlike the GTX) and pretty close to the X1950Pro in power requirements, but noticeably less than an XT.
http://www.xbitlabs.com/articles/video/display/geforce7950gt_3.html#sect0
So the main thing is to check the games you play on and decide from there.
BTW, that link isn't fro current performance (which changes since las tyear when that was tested) but for power consumption, which doesn't really change over time.
IMO, the GF8600GT/GTS won't be worth it for any of the new games as a DX10 card, and running DX9 like HY27 aid, they're not going to be stellar and will play in and around the same level of the X1950Pro and GF7950GT if not worse.