Yup, so far so good.
A note: install your 3rd party plugins BEFORE loading your previous sessions.
I installed the base SW, then loaded my old PC sessions (which set all the 3rd party plugins inactive). I was impatient

.
After I installed the plugins, I tried to activate the plugin instances and it didn't like that. I could remove them and add new ones no problem though so I just did that.
I am floored by the performance increase (PC: Pentium4 2.4GHz w/ 1GB RAM to iMac: 2.8GHz CoreDuo w/ 2GB RAM). It used to take ~20sec to load on my PC and the CPU monitor would be about 1/2 on a decently busy session.
Now, it loads in about ~2sec, and barely registers on the CPU meter
Of course, a new PC would also show similar gains but hey, I'm still in the "honeymoon period" with my new iMac.
Later
Rob