I can confirm that there is an additional fps boost while using 12.1. I have a 2GB 6970 so anyone with that line or just up to trying regardless, link is in the OP.
I have the same card and I'm running 11.11c right now which seem ok, but I'll give the 12.1 drivers a shot.
Downloading this off steam right now. I have a slightly OC'd 580, and a 2600k@4.2, any recommendations on settings etc?
You should be fine on Ultra settings, maybe with shadows turned down to High. I have a 6970 and a 2600k @ 4.4 and I hit 60 fps most of the time out in the open, cities can be anywhere from 30-60fps though. 1080p btw.
You probably want to up your uGrids count to 7 as well, there is a guide in the OP and plenty of other tweaks you can try for more eye-candy seeing as you have a pretty beefy pc.