*ON* direct hardware for Window*...
Why not settle for good enough on Virtual Hardware. And the machines you should be running a VM on should be much faster than your old machine in any case.
You obviously aren't running current VM technology, as *I* do not notice speeds falling off on VMs running VMware Fusion v1 (yes I know there is a free upgrade...)
WindowsXP seems to be *MUCH* faster on the VM than it was on Baremetal (being a direct copy from an Athlon64 3500+)
So what gives with that "but one is always aware that it's not as fast as being directly on the hardware" comment?
Personally, I've never used Parallels, so if that is the case, I'm sorry for you.