the 2600 don't compare to the 8600gts in DX10 games. They are nice cards, but at 150$, the Nvidia one is the nicer bang for the buck!
I got mine for 200 a while back, and I was looking online just like you to decide whether or not to get the 2600xt.
I'm tempted to pick up another and sli them up. (faster than a 8800gt)