Flashed 2012-03-30 nightly and running great so far!
I modified the ROM zip before flashing:
1) Added Gapps and FaceUnlock directly to the ROM so no need to flash later
2) Added my own custom ringtones, alarms, notifications
3) Replaced the CM9 boot animation with the ICS boot animation (which I prefer)
Flashed my modified zip file without clearing any caches, or data, and all is well so far. Still testing but it seems to be working very well.
I'm using Icy Glitch v14 B6 kernel with a LiveOC of 120%