Something to be careful of is that if there was not version with XP on it that there may not be XP drivers for some of your hardware. Ethernet/Video may be easy enough but if you got a vaio with a cam for instance, you may not be able to use it all with XP as it was never designed for XP.
XP has ALOT of driver support so if your comfortable wiping and letting plug and play and some google-fu find stuff, have at it.