I've mostly been installing Pro or Ultimate. The Home versions only drive me up a wall with their limitations with regard to networking and such.
I also have it installed on a vintage 2003 desktop with 4 gig ram, sata hard drives and dvd/rw. I did have to find a software upgrade for my brother 4 in 1 to install scan on the desktop (the vista drivers work fine). I used an upgrade on this pc, but did a clean install on the drive.
I've been very happy with Windows 7.