If the nightly builds of CyanogenMod-6, a custom ROM based on Android 2.2, were a little too pre-alpha for your HTC EVO 4G's tastes, then maybe its palette will be pleased by the release candidate that has just been made available today. It still isn't in final form, of course, but Cyanogen says that "you will find it stable for everyday use." Many users were already finding the nightly builds to be quite stable, so the release candidate should be pretty solid.
There are lots of goodies to be enjoyed in CM6 (V6.0.0-RC1), but what you won't find just yet are functional HDMI, 4G, or FM radio. Facebook contact sync isn't working and protected apps don't show in Android Market either, though there may be some fixes for these two issues somewhere in the xda-developers forum's EVO dev section.
Anyone ditch the nightly build for the release candidate yet?