The proof is in the pudding. Take two 6/O or so circle hooks and crimp one and snell the other. make an open fist and put hooks inside. do several pulls on the leader at different angles and speeds. It will be obvious which method is more effective---- the snell.
I've seen it done both ways and like Glenn I prefer the snell because it holds the hook in a stiff position for it to slide into the jaw. The crimp lets it flop around too much.
Plus I think the snell is pretty close to a 100 percent knot, but if you crimp a batch of rigs incorrectly then the crimps will cut into the leader a little bit and weaken it. With a snell the hook will straighten before the connection breaks.