I own both Parallels Desktop and VMware Fusion, although I’ve been using Parallels mainly because VMware had a problem with Visual Studio and shared folders. Parallels did feel nicer running Windows XP, although it slowed down my system pretty badly, even with 4GB RAM.
Even though I was getting disgusted with Parallels’ terrible Linux support and the system slowdowns & freezes, I couldn’t use VMware because I was unable to check out files or download changes from Visual Studio to my shared folder, and Parallels didn’t have that problem. After attempting to get Ubuntu 8.04 and OpenSolaris running in Parallels, I ended up installing VMware Fusion along with it so I could run the latest Ubuntu, which wouldn’t even start in Parallels, while still using Parallels to run Windows.
The VMWare 2.0 beta released today seems to have fixed the problem (mostly). It still shows ‘error 1’ in Visual Studio’s log when I check out files from VSTS, although it actually completes properly. VMware generally seems less hackish than parallels and doesn’t slow down my Mac as much. I can even have two VMs running at the same time with no problem.