Actually this leads into another theory of mine, the extra wide (24+") stances that some guys ride with now actually hurt their park performance. The bindings, boots, and your lower legs are that much further apart making it take more energy to spin at the same spin speed.
Yeah I think this is pretty much accepted fact. the compromise is that the wider stance gives you better balance for jibs. since the guys riding most parks aren't throwing double cork 12s, the tradeoff for jibs in favor of spin is a no-brainer. That said, if you're 5'8" and rocking a 24" stance you might wanna reconsider