I have tried many different 2.2 Froyo ROMs, and so far, I have found Kangarade 1.1 with jdlfg's 1.0GHz kernel to be very stable for me. I love the no FCs and awesome battery life (consistently on at 1 day and 14-23 hours with medium use). Plus, like any ROMs, you can customize this to your heart's content, esp with CW Recovery.
All 2.2 Roms are skins on P3Droids froyo release right now for the droid. They all run on top of that, so no matter the ROM, it is still the same 2.2, and the differences are going to be visual only (maybe some scripts) A kernel will make a difference in performance though. If you have some time, I recommend trying a a few of them. I think SD ROMS look really good ; )