Nvidia 7600GT seems like a really nice card actually. In one review where they compared a 6800GT to the 7600GT I found this.

Battlefield 2

7600 GT

6800 GT

1024 x 768

86.04 fps

52.41 fps

1600 x 1200

49.83 fps

32.02 fps

2048 x 1536

34.51 fps

16.95 fps

During other games though, the difference is smaller, usually the 7600GT is around 20-30% faster.