The 7950s are impressive and they overclock really easy, an overclocked 7970 would still be faster but for the price of the 7950 and it matching the 7970 at stock when OC'd it is the much better buy.
I have read you can flash the 7950s that have the dual BIOS with an Asus 7970 BIOS and it improves performance but it doesn't unlock the shaders. Don't know how true that is but it's what I have read.
Prices are still to high for the 7950 and 7970 though, but I think that is more to do with AMD taking advantage of having better cards than Nvidia on the market at the moment, anyone buying new or upgrading will be buying a 7970>7950>580. Once Kelper comes out, hopefully soon, prices will most likely drop, unless Nvidia price their cards really high as well.
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