Wow, thanks! Great stuff!
The advice about same-sized RAM is rock-solid, no matter which OS you're running....all the way back. You'll definitely see a performance boost when you bring them all in line.
WinClone is a great app for backing up your Boot Camp partition.
I wrote about it here, with a variety of backup tips.
Don't forget that in Vista, you've also got a fantastic built-in back-up tool. I've been fortunate enough not to have a disk failure so far, but this is how I'll recover.
Agreed that both XP and Vista virtual machines could cause a mess. I like the sound of your set-up.
Thanks again for the great report!
Tim