I'm using a Samsung Galaxy S (the first one) with some prerelease build of CyanogenMod 9. Performance is perfectly fine, unlike when I had 2.3-based Cyanogen on it. It's just barely daily driver-worthy, the 3G radio turns off about once a week and there's a few other hangups that would make me never ever recommend this setup to a 'normal' person, but it beats running 2.3. I'm probably gonna ditch it when the next iPhone comes out.