Quoted from Grauwulf:I think the main benefit to using the WPC flipper mechs is to get rid of the cone style flipper return springs. It's more expensive than a rebuild kit and honestly I don't feel it's worth the extra money for a machine that's only going to see home use. If you get a flipper rebuild kit they typically include the capacitors in the kit for you to add. The benefit to the caps is just to slow the pitting and wear on the EOS switches to make them last longer.
I switched mine over to the standard simply because my other games were WPC (or were switched over prior to my owning them.) so it makes it a little easier to order (and less parts to store)