I think it all depends on what you hunt. I have killed whitetails,turkey,black bear, moose, dall sheep,and caribou with a bow. None of the critters up here will duck or jump a shot. I shoot arrows that weigh well over 500 grains because I want penetratiion for Alaska animals, and my bow has a draw eight of about 72lbs. But I have to say that whitetails have done some crazy shiznit to me with a bow in hand. If I were hunting wiley whitetails, I would want the fastest and quietest bow/arrow combination that shot well. But for larger animals with bigger vital areas and not quite the cat like agility to avoid an arrow, penetration is key. We regularly shoot animals with a bow up here at or past 50 yards. A buddy whacked a Grizzly at 62 yards with an arrow that weighed near 600 grains and was being pushed by a 70+lb draw weight. Heavier arrows tend to stabilize (read buck the wind) better than lighter arrows , and also tend to be more forgiving. All depends on what your hunting me thinks.
