I'm running CM 7 nightly, but you have to be very good at beta testing in order to keep up with this ROM, particularly if you have a lot of apps installed and / or have a lot of apps that run in the background. Gingerbread is highly aggressive in terms of freeing up RAM so that applications can run, and it will do things that at first seem strange to you if you're not ready for it.
Jerry's last link is a good place to read (meaning read before you just jump on board and try one) about most of the different ROM options out there for the phone.