680 is still faster than 960 actually. The only advantage of 960 is it use much less power than 680 that you can get away with small PSU.
Now this is where it can get complicated. 960 is new so most likely the card get better attention by nvidia. Also there were lots of complain how nvidia gimping Kepler so they can sell Maxwell. That aside the way I see it Maxwell is simply more of a gaming card than that of Kepler. We see GCN based card catch up a lot and even surpased Kepler to certain extend (like 7970 which supposed to compete with 680 now able to catch up with 780). So having all console hardware using AMD gpu architecture might have it's advantage after all. Now more and more game engine get tweaked with AMD architecture as a...