First of all, the OP is about a 6950, not a 6970. XBit tested 14 games and the 6950 was only faster in 1. That pretty much rules out his supposition the 6950 might be faster.
Second, with cards this fast, who is at 75fps and who is 80fps starts to take a back seat in the buying criteria. As both 75 and 80fps are impossible to tell apart while gaming, you need to consider what else the card can do that the other can't.
PhysX- every year more games come out with GPU accelerated physics effects that you can only see on NVIDIA cards. Adds to the level of immersion in the game, makes games more realistic.
CUDA-is the defacto standard for GPGPU computing, waaayyy ahead of ATi's "STREAM"
3d Vision- IMO, the most important factor in purchasing a card. I've purchased five 3d monitors myself I like it so much.
3d Vision Surround- the reason I purchased five 3d monitors. Nothing in gaming tops this, or even comes close.
Forced ambient occlusion- more realistic lighting = more realism
Single card 3 panel surround- this is great, but a double edged sword. As a person with a 50 X 10 set of monitors and a 57 X 10 set of monitors, I can tell you that having two GPUs doing the work is preferable. Check out the benches of these cards at 25X16, then consider that even three 16X10 panels is 1m more pixels to push. These are super high res solutions, and the need for two gpus (esp at 1080p and up) largely negates this "advantage".
STREAM-Haven't seen much about this. Doesn't seem to be catching on with anyone.
"Open Platform 3d" - this is just weak. Limited to 24fps at 1080P resolution, no monitors for sale in North America, have to buy 3rd party IZ3d or DDD software and play it on tvs at 720p. This is more like a high school science project than a commercial product.
Open CL Physics games: NVIDIA could do this as well, if any existed or were in development. As it is, I think I have twelve games with PhysX, and more are on the way.
6+ panel Eyefinity- go to a trade show and play with this, I guarantee looking through the grate of bezels at the games won't make you want to pony up the dough for an elaborate monitor rack, dual dvi extender cables, or 6+ panels. It is a monstrosity. 3 panels work, and work well because no bezels split the main action and they're easy to ignore in your peripheral vision. With 6+, bezels split everything
. If you make two or three hundred thousand a year and can afford a bank of the new ultra thin bezel panels, this would be very cool.