I've had quite good luck with Parallels (released versions and mostly the latest betas) with XP and Linux. My recent experiences with Win 2000 haven't been so positive. I've had much higher CPU utilization with W2K (about 50% or more of a cpu on a MacBook Pro C2D) and many crashes of parallels. Often if I leave the W2K running (not really doing anything) I'll come back to find the VM has crashed and the dialog box asking whether I want to report a bug to Parallels HQ (which I always do). Neither XP (Bootcamp) or Ubuntu Linux have shown either of those problems under Parallels 3188. The final straw on my Parallels W2K VM was when the VM crashed while MS Money 2006 was running. A large number of files were damaged and when chkdsk got done with fixing all the cross linked files, etc (100s of them) the VM was left in a state where W2K wouldn't boot anymore. There is a BSOD which flashes a message so quickly that I can't read it and then the VM resets and tries to boot again, over and over. Fortunately, I had just recently migrated the Parallels W2K image over to VMWare Fusion, where it is happily working away with no crashes and no high CPU utilization. Since this was a complete image of the Parallels VM, I didn't loose anything when the Parallels W2K version went belly up. But I don't think I will be migrating the W2K VM back to Parallels until the W2K support improves.
