It seems like the performance tails off at high res. so I might be better off with a GTS at 1920x1200. I *really* want this card to shine so that I can finally turn all my games up on my monitor. 
I thought the card would be awesome at high res considering the 512 bit bus? All the specifications put it ahead of a GTX but it doesn't perform like one. Could someone explain this for me?

I thought the card would be awesome at high res considering the 512 bit bus? All the specifications put it ahead of a GTX but it doesn't perform like one. Could someone explain this for me?