The 2900Pro 256-bit card is still a great deal. The 256-bit bus doesn't seem to affect performance at all. Just keep in mind that the 3870/3850 and the 8800GT/GTS G92 use a 256-bit bus. It is extremely overclockable. I have mine at 850/1000 and I get 11k in 3Dmark06. It's a little loud but for the performance and price you can't beat it.
I run Crysis with it using the DX9 Very High mod and I get about 30FPS @1280x720. I highly recommend this card to anyone that doesn't have a $10 dollar PSU. The power requirements aren't as high as the old Pro or XT because it only needs one 6-pin or 8-pin adapter to run it. They are going on Newegg for $159 right now, I was lucky and picked mine up for $130.