Correct me if I'm wrong, but I find it odd nVidia finally put out a high and extremely high end (670 and 680 respectively, obviously) with the same amount of vram. It seems that the 670 is not even a neutered 680, it's just a slightly younger brother that easily holds his own.

I wonder how gtx 480/580 sales would have changed if the 470/570 had the same vram as the others (yes, I know there's a 2.5gb 570).

Unless you're benching, I see almost no reason to get a 680 unless you need the 4gb version (and that extra 2gb has yet to be needed, unless there's a review of it w/ 5760x1200 out somewhere).