So far as I recall, only through the hit or miss unlocking of 6850's into 6870's did ATI beat nvidia in price/performance. And with the advent of the quite affordable factory overclocked 560ti's, that advantage has been gone for awhile. And quite frankly, I have several Nvidia based rigs (8600gt, 9500gt, ion, 335m, 460m, 560m, 560ti, quadro 6000), and I've never, ever had driver issues, even with beta drivers. The ati systems I have dealt with (e-350 apu, 4610, 5870m and some old x1600) have been fraught with issues. The e-350's were pretty painless, but I never could get the 4610 to take a driver update without fritzing out and crashing. And the 5870 in the g73, well, 11 restarts, 2 BSODs and more than a few non fatal crashes was all it took to update drivers successfully. Which actually decreased render performance in solidworks, all said and done. Never did get the 4610 working; just replaced with an old 8600gt, which dropped in and worked fine.
For overclocking, I can honestly say I've never tried overclocking an ati chip, since its enough of a pain in the ass to get the things run normally. My 560ti has been nothing but a pleasure to overclock. Sitting happy at 975mhz since november with no trouble. And a 4xsli gtx 680 rig just took the performance crown in the 3dmark 11 hall of fame.
For current pricing, yeah, nvidia is more expensive, because they cant keep up with production. The 7970 has a $50 higher msrp, so when nvidia gets production ramped up, the ati is gonna cost more.
All said and done, I firmly believe nvidia to be better. I suppose when 80% of your experience with a company has been a complete pain in your ass, you tend to dislike their product. Stack on that all of nvidia's goodies, like physx, cuda, and better 3d support, and it pretty much follows that Nvidia is better.
I've been getting a lot of issues lately relating to drivers, having to restart my PC a few times sometimes to not get 5fps out of CS:S playing on minimum for some reason from my 560Ti.
In terms of OCing, the 7970 is hugely underclocked from what it's rated to do from the factory, meaning you can OC way beyond stock where it's at the same performance as a 680. Not sure how that 680 beat a quad 7970 setup either, AMD is on top for multi card scaling right now also. As well, 3D drivers if anything should be easier to deal with on AMD cards, since third party drivers mean that you don't need to mess around with special Nvidia monitors and flax. Physx is also still useless.
I also don't want a card that's like having 3 lightbulbs in a shoe.