I know many people have been waiting for tests like these.   While this is most likely the first of many comparisons, we should keep our eye out for more:
 
http://benchmarkreviews.c...p;id=971&Itemid=72
 
Basically it boils down to this:  660Ti is right behind the 670 in terms of performance in most games when running a single card, making it an incredible value.  Now, when run in SLI the game changes significantly and the 670's pull much farther ahead in all games but one tested.
 
Just trying to provide some insight for those of you on the fence.  Best of luck deciding on your future purchases:)

I think the 660 is priced just right for its performance. The 670 from most benchmarks I've seen is about an average of 10 fps ahead the 660. Seem like the 660 can definitely hold its own but when it comes to gpu intensive games the 670 comes out as the leader everytime. It's not nearly as close as the 670 was to the 680. Which puts it right in its place as a budget card like the 560 was.