So yes, it is faster than the HD 4870 X2, but if you already have HD 4870 X2, no need to upgrade, playable FPS starts at 60, only game which doesn't do 60 is FC2, and here GTX 295 is faster, but not enough to make you spend in my humble opinion.
10% at 2560x1600 4xAA where the HD 4870 X2 is already providing playable FPS.
Crysis is missing from the benches, the only game I think where the GTX 295 will dominate, while other games like GRID it might be humbled