The game runs great on a HD6950 if you do not mind the ATI blue stripes.
I am sure a cure for the stripes will be on hand soon.
The blue stipes are a known issue of the 6xxx series in the game and i would seriously doubt you would be lucky enough to buy one that does not have the problem.
As for other games it is awesome. Only problems games are Clod and mount and blade fire and sword, but the later has always had issues with ati graphics cards.
I am given to understand that only one member of the clod development team is using an ati which could explain the problem not being fixed yet
it is unlikely they would dare release the game in the US without addressing the ati issues considering the massive ati support in the US