The proponents of a deep hook have convinced me. Look at your hand and forearm with the fingers flat and perpendicular to your wrist and then push forward on the fingers with your other hand. Your string hand and wrist is all tensed up against the forward pull (push in this case).
This makes it difficult for me to relax my hand and get a clean release. With the finger tips pointed back toward me, all the tension is coming from my back. When I decide to shoot, my hand is already pretty relaxed and seems to snap out of the way better.
I shoot with some guys who are far better shots than I and some of them shoot off their finger tip pads. Just doesn't work for me.