After two days of using Beta 4 I had no restarts (except the one I tried to launch camera xD) but experienced lots of flickering. App just freezes and starts to flicker. I can of course kill it with holding back button but it can be a little annoying.
Rest of known issiues like random MAC or lack of auto brightness aren't that terrible, however I hope they will be solved in Beta 5. For now pretty stable and very fast ROM ;] Good work DJ Steve and giveen!