We've been using Parallels for the past 6 months on one of our Intel mac machines. We recently purchased another copy for a new iMac. I've never tried their competition (VMware Fusion), so I can't comment on that, but I do want to say that we've run Parallels basically 24/7, and it's never, ever crashed or froze up. It loads XP incredibly fast, and all of the apps we run on it are stable. We've actually never gotten even a spinning beach ball. In a way, it's more stable than Leopard.

We're about to push the limits a bit by switching to Windows Quickbooks so that we can use its networking capabilites between Macs, so we may discover an issue there. But I wanted to post our results so that others know that, at least on our setup, Parallels is just one of those rock-solid applications.