I'm about an inch from buying an HD5770, I want the DX11 and speed. I also plan on CF'ing it when I get the money for a second.
Anyhow, I've seen a couple reviews that mark 128bit memory as a con, what's the difference? Is it going to decrease overclocking room? I don't even know when the memory of your video card is used that intensively though, I've overclocked mine pretty heavily before and never saw a difference :-/