I highly recomend the MSI twin frozr III 7950. Game framrates are pretty much a not an issue at 1080p anyways, so it comes down to the bitcoin advantage of the AMD or the CUDA advantage of the NIVIDIA.
I have vsync on because I have a bottom line 1080p monitor so most games sit between 50-60fps with the exeption of Crysis 3 and Metro 2033 bottoming about 30fps on intense scenes but usually between 45-60fps... with the 7950 at stock clocks. Overclocks amazingly too with some nice framerate boosts. Nice name Nilloc!
People say the GTX 670 performs better, but when you overclock both... the HD 7950 comes out top. It's also quite a bit cheaper. So I say go for the HD 7950.
almost all benchmarks are too old to be accurate. AMD has been doing some wizardry with their drivers, and almost all the benchmarks i've see are from before the new drivers