I own the latest versions of both Parallels and Fusion and can say without a doubt that Fusion is faster and more efficient than Parallels when used with XP.
Me too. I run VM ware and Parallels (using XP) on two identical iMacs, and it sure SEEMS like VM is snappier. Not sure what to make of this. For certain I much prefer VMware's interface and it seems more stable than Parallels.
For what it's worth, I recently got Dragon Naturally Speaking 9 Preferred to work in VMware Fusion /XP (took a little doing...) and it is actually quite useable. I think it is faster and more accurate than it was on the WinPC I tried DNS (v.6) on a few years ago.