It's beautiful, totally fast, and scarily smooth, but keep the following in mind:
- It's more unstable than CM7 Alpha 1. It will restart on you if you make it angry (which is quite easy to do). It's probably wise to stay on Gingerbread for some time.
- It's completely open source now, so it will probably be updated much faster/more frequently in the coming days.
- If you have problems with some apps after updating, uninstall them and re-install them.
- Some say overclocking doesn't work. (That's not true for me. I can do a full 1.7 GHz with no crashes.)
- Before installing ICS, make a backup in Clockworkmod Recovery, in case you don't like ICS and want to revert back to GB.