I recently upgraded my AMD 2800+ to a Intel Core 2 Duo 3.06GHz and 7200k RPM HDD. My attempts to run Virtualbox 2 on the AMD system proved futile: the computer just wasn’t fast enough. I ended up maintaining a dual-boot system–most recently Windows 7 and Ubuntu 9.04.
I also installed OpenSUSE 11.1 to do some unit tests in Konqueror and then installed Qimo linux to see if it would be good for my 2 and 5 year old. (Linux for Kids)
I specifically got a Core 2 with the new Virtualization support which somehow magically speeds up virtual environments such as VirtualBox. VirtualBox 3 can now take advantage of it. VirtualBox kicks butt.