I have Vista 64 and am running it without much headache, but I chalk that up to being somewhat of a geek. In other words I’ve tuned it, found where the problem areas are and eliminated them. So I’m in no rush to pickup W7, but next time I’m at the store and see it I will grab the home 3 PC warning.
One word of warning however, if you have Windows movie maker I understand that W7 doesn’t come with it. That means a lengthy (but I think free) download after install.