@lostforever - I finally got around to running some benchmarks with the GTX 770. I only tested two games (I didn't have much time for comparison tests because I already had my GTX 470 sold on Ebay) but the results are fairly impressive.
In Tomb Raider @1920x1200 with all settings at maximum + TressFX. Using the built-in benchmark, my fps went from…
Min = 12.5
Max = 33.0
Ave = 23.4
to…
Min = 26.3
Max = 62.3
Ave = 47.7
In Metro 2033 @1920x1200 with everything maxed + Advanced PhysX, I went from around 23 fps to around 50 fps. (Used Fraps)
Considering that I haven't touched the rest of my system yet, I'm quite happy with those results. With the CPU and RAM you have, you should see a significantly larger increase if you were to upgrade your GTX 460 to a 770.
*Edit* I should probably add that I also had vsync enabled during those tests, otherwise the fps might have been considerably higher. I didn't see the point in disabling vsync for the benchmarks though because I always use it when gaming.