Been on XXLP2 for over 24 hours now, had a couple of lock-ups at first but I'm sure that was due to sync/download bottlenecks, and 1 Launcher Pro FC after changing prefs to single home screen.
Scrolling is "stiffer" ie. less fluid/more resistance, slightly slower page loading in browser and apps etc. don't open as snappily as I'm used to in CR/Siyah... but that's just running LP2 as is. Down to 80% battery in around 15 houra since last charge and that's with what I would call moderate use, probably light to the gamers among us.
That LP1 modem is superb, particularly for phone reception, it hasn't wavered from full signal bars and calls connect at land line speed!
I'm liking ICS on first impressions and it can surely only get better, especially when the devs get customising.