well, i have the 7600 gt and will agree that at stock it is better than then the 6800gs. BUt when it comes to overclocking, the 7600gt definately does not overclock as high as the 6800gs. Also, though the 128bit interface does not seem like a big deal right now, but when you try to run a game with 4xAA, the 128 bit interface becomes clear of why it is better to have a 256 bit.
I got the 7600gt though becuase i feel it is one of the best bang for the buck cards. It is going for very cheap right now as i have seen it in the 150 range at newegg(with rebate) i say take advantage of this card, than ride it out till dx10