To be very specific I only seen like 2-3fps more at the end of my total bench on Heaven.
Here is my best bench.
17:01:02 Time: 259.512
17:01:02 Frames: 10679
17:01:02 FPS: 41.1503
17:01:02 Min FPS: 21.5806
17:01:02 Max FPS: 90.0593
17:01:02 Scores: 1036.58
So...
I can confirm the modded 6950 BIOS script works well. Very stable just unlocking shader count. Here is the card setup I have just recently done with a brand new 6950.
Video Card :: 2GB Sapphire Radeon 6950 HD. No 6970 BIOS voltage/clocks flash. But OC'ed and flashed w/modded 6950 BIOS to...
What brand is your 6950? I just bought a 2GB Sapphire Radeon HD 6950 and thinking a lot of things over. I see you had an unsuccessful attempt at flashing with the first guide that has been up. They really should update that.
Considering you're dealing with 6+8 6970 vs dual 6 PCI E on 6950...