Back when the V7700 was first released it may have been better than the Gaming class GPUs. Now though I doubt it would be faster/better than a 6950 in any respect.
As more home users have been doing activities such as video editing and rendering on their home computers GPU manufacturers have been releasing more GPU compute based functionality on the consumer level GPUs. The NVidia Fermi architecture is a very good example of this as the GPUs in all of the NVidia range are highly GPU compute orientated. On the AMD boards the GPU compute ability is more limited to the more expensive GPU range such as the 6900 class.
All up ... the 6950 would be considerably better for rendering AND Gaming than the V7700