I don't know why people keep saying these things.
The W9000 performs almost identically to the 7970GE in terms of performance in gaming. That's because they are almost identical in terms of chipset (Tahiti), clock, stream processors, etc.
Workstation GPU are consumer GPU plus a few extra features and professional application/driver support.
Well considering the benchmarks provided just a few above yours showing the 7970 GE outperforming the w9000 in Heaven by 15% I would say that he's workstation GPUs are not as good at gaming as consumer GPUs.....