I'm working on a gaming computer build, and I'm trying to decide whether performance upgrade with the GTX 670 warrants a $100 price increase. I don't need the absolute best, I just want to play games like skyrim (with several mods/ENB) and new releases (dishonored/bioshock infinite) at ultra settings. However, I don't want my card to become obsolete within 2 years.
I'll be using a 1920 x 1080p resolution monitor, and an i5-3570 intel processor, so no bottleneck there. The GTX 670 model I'm looking at is the Gigabyte Windforce (shown below), and I don't really know what to look for in 660 ti models, though I've looked at benchmarks.
If your budget allows it get a 670. The crippled memory bus of the 660 ti will restrict it over the course of its use. The high end 670's arent far off a reference 680. The MSI Powere edition with a mild overclock will be faster than the 680. You will see a gain with a 670, but really it depends on the budget.
Were it me, I would spend the $100, and not look back. But not everyone can spend $100 just to reassure themselves.
I would scan the Tom's benchtests on the 660 TI to get an idea of how it works on ultra type settings on various games at 1080p. For example, in Battlefield 2, the 660 TI gives up very little. In Skyrim, it gives up 10 fps if I read that right.