You're talking like 5-8 fps is nothing. Thats in fact a 5-10% performance.
No, the 670 is not the same price as the 7970.
Take a look at PCPartPicker:
MSI,
Gigabyte and
ASUS.
We can conclude that the 7950 is at $315, the 670 is at $370, the 7970 is at $405 and the 7970 GE is at $450.
According to Tech Power UP:
http://tpucdn.com/reviews/AMD/Cataly..._1920_1200.gif , the only card that is able to beat the $670 is the 7970 GE at a $80 price premium (+22%).
You're paying an additional $45 (+12%) for the 7970, yet it doesn't have superior WoW performance, even with Catalyst 12.11.
Everyone needs to stop blindly recommending AMD based off of the over-hyped Catalyst 12.11 drivers.