I do't use my PC for game anymore (well except STALKER) I use it for transcoding via my 4870OC GPU. Looking transcoding benchmarks, there is no advantage having a 5870 over a 5750. I may get the latter for the future DX11 direct compute/Open Cl potential. A slight stepdown in gaming performance, but a benefit for transcoding and price :-)
It seems like very few people use the GPU for transcoding. I wonder what the real percentage of GPGPU users is?