Ok guys after much thought this morning, I've decided to go with 2 7970s Vapor-X Editions. Not only do they smoke the 670 at higher resolutions, but can OC incredibly well.
If driver issues are truly a problem, I can always return both cards in 30 days to Newegg and get a pair of 670s.
Huzzah for that choice.
My past two setups for vid cards have been 2xATI for CF goodness.
I never had driver / perfromance issues, just extra heat and noise.
It seems many ppl are shortsighted this vid card go around.
AMD made the 7950 and 7970 very future proof with 3GB VRAM and optional OC goodness.
And the aftermarket non-reference cards are amazing.
I plan on keeping my 7950 and adding CF in about 6 months, then keeping that for 2 years.
If anything, nVidia is overpriced with Kepler.
Dare I say, the 7950 is like the 2500k. Awesome value, can OC like a champ.