Update from my side... After three days running 32-bit 11.04 everything is still running great with a couple minor exceptions. I have noticed that I am seeing the problem with stuttering video playback after suspend. I tried the workaround at the link that you cited, but it didn't work for me. Not that big of a deal to me, but I gotta strive for perfection.
The only other quirk I've seen is that when I'm running the proprietary nvidia graphics with dual monitors, the KDE desktop effects (compiz?) get disabled whenever the monitors power down due to inactivity. When I get some time I'll look for a workaround for that.
Otherwise it's working great.
Did you make sure the script shutting down cpu's is executable?