I have been sitting back and following this post for quite some time and I have learned a lot, gotten confused by some of the math, and been thoroughly entertained by the Silentassassin vs. ArthurP (and company) banter. You two remind me of football where there are two quarterbacks fighting for a position. The grizzled veteren with the military haircut that stays in the pocket and lobs passes to his receivers with remarkable precision picking his way toward a touchdown and the flashy kid out of college with his sunglasses and gold teeth who can't wait for his receivers to get open so he takes off himself screaming down the field juking linebackers all the way to the end zone where he does his celebration dance.
Believe it or not this analogy does have something to do with the topic at hand. My contention is that with a slower set up (round wheels, soft cams, traditional gear) and longer draw lengths you are better off with heavier arrows that will store more of the limited energy that you have. Arthur, let's face it you won't be straining your round wheel bow too much with lighter arrows. On the other hand, with a setup designed for speed and shorter draw lengths, which includes many of today's bows, you are better off with lighter arrows that will translate much of that stored energy into speed and create high amounts of KE with the higher fps. Silentassassin, your setup falls into this category (as does mine since our setups are almost identical), but would you be willing to use that setup to hunt cape buffalo in Africa? I know I wouldn't, but I wouldn't want that slow log flinging setup either.
Bottom line is each arrow application has its place with different setups and different archers.