No matter what "horses" you have, they will run faster on XP than on Vista. Saying "If you have the horses to run it" is misleading because to do the same things, with the same results, Vista requires many MANY extra paranoid "security" (DRM) checks whereas XP does not. One example is a series of instructions in the code; to perform a task in XP it used to take (i.e.) 5 steps, but in Vista the same task takes 11 or more, because it's making sure that nobody has hacked the PCI bus between the sound card and the CPU and other retarded sh**. Oh, and don't forget all the code that makes your sounds and displays WORSE (on purpose) if they are not "secure" (which by definition they cannot be).
Vista is a POS.
If you're concerned about your "horses" you'll run the same horses on XP and get better results.