the 7970 is not the best in a price/performance ratio but it is the fastest single gpu card out there. and if you have some liquid nitrogen laying around you could make it faster than any dual gpu card that is at stock speeds. but thats overkill and short term
it is a very nice card im using one right now and i have only had 3 small problems with it.
1. starwars the force unleased II, was very dificult to change the resolution when in eyefinity mode. the game doesnt support eyefinity but normally a game will just let me play single monitor as if the other two dont exist. this one gave errors and when it did work it would cut off huge portions of the screen. i did get it to work as i could see the drop down for resolution and hitting q, w, or e made it accept the changes.
2.skyrim would give errors when changing settings. i would restart the game and it had the new settings and ran fine but it did give errors and crash. so no real biggie.
3.in most of my games there are small glitches where reflections or shadows should be. they arent terribly noticeable or annoying. Im sure they will be fixed in a few driver patches.