I reckon the 680 is loosing a bit of ground to the 580 due to the price to performance ratio;
http://www.videocard...GeForce GTX 680 life is fickle - your top dog one day and old news the next
Best to do a final check before ordering to see what is deemed the best on that day.
While I agree with you on the note that it would be more fiscally responsible to go with the GTX 580 given those scores, I'm more concerned with overall graphical performance rather than the performance/cost ratio. In that regard the 680 still seems the better choice.
Additionally I don't plan on overclocking this systems and to that end I believe that the 680 is also less power-hungry than it's non-kepler brethren. I'm not positive of this however.
Still though, thank you for the information, I will make a note to check it regularly as time goes on.