just flashed 0.3.1 yesterday, after going from ROCKO 1.1.1
I have to say, the OS is soooo much cleaner, well integrated, much more responsive, sensitive, and fluid. When underclocking to 800Mhz, this thing runs more fluid then it ever did on stock gingerbread. When underclocking to 1Ghz, this thing flies (yes, underclocking).
Given the way this thing runs, for a locked, unrooted user, i'd probably upgrade to ICS in a heartbeat, although I'm sure blur will lag the heck out of the system. The only thing is that ICS, i feel, is made for screens that are slightly wider in aspect ratio. I find that it can seem a bit cramped, but the way CM9 has been running for me, i'm never going back to gingerbread.
@drexappeal, after looking at the leaks, i don't think i'll be going back to stock and installing the moto version of ICS...that's just fugly...