Its so weird that the GTX460 (which equals the 6850 which equals the 7770) used to be a really good mid range card that could hold its own in several games.
Honestly it still can, but it is categorized as a lower end card now. Its ridiculous how fast things move.
Honestly OP, if your computer performs to your liking, I wouldnt change a thing. If you feel something lacking, the first thing to change would be the GPU since the CPU still has some headroom.