I used maacruz kernel(pwck2) and experienced massive UI/graphical lags and even lock-ups, nothing is responding to input and needed to put my N900 away, till cpu/IO load was lessened . Then went back to omap1 (stock) and didn't experience anylags or lock-ups. BTW I used max freq = 900 mhz with SR on maacruz kernel. So maybe one of the patches was bugging. Trying pw49 now..