I started my cab with WinXp but had a lot of stutter. The whole system isn't that bad but not a "monster". I switched over to win7 64bit just
to see if there is some speed improvement...and man wow the graphic card drivers are mucht better optimized for that OS. No stutter at all even
on the "big" tables like Star Wars Trilogy, Big Bang Bar or Creatures form the Black Lagoon... so my advice is: use win7 64bit if you have a more
or less up to date system and forget WinXp.
On my system, VP DX7 does not run well under Win7 or Win8. It seems like any table that uses the modern primitive features got very poor framerates. Under XP, the same poor performing tables on the same hardware will have framerates that are at least 3x higher.
However, the DX9 version, the tables turn, and Win8.1 is clearly faster and more stable than XP. The XP drivers for my NVidia GTX 650ti are also buggy. We were able to work around one glaring problem (unable to create 1x1 textures), but I would sometimes get freezing under DX9 that was completely eliminated under Win7 or Win8. XP also has annoying start-up delays and issues with VPInMame on a 3 screen setup, where I intermittently can't use DirectDraw or Direct3D modes.
I also noticed that B2S takes a bigger hit on performance under XP. Under Win8 or Win7 it doesn't seem to much matter what the B2S is doing, my table performance stays good. Under XP, some backglasses cause stutter.
Win7 had an annoying delay exiting tables on HyperPin. Under Win8.1 the table exits just as fast as it did on XP.
So I definitely think it's time to forget XP, once the DX9 port is finalized.