You stated:
<<<my question is How much control do you have in one of these? More or
less than a mechanical hack? More than a sidepull? Is whoa an option?>>>
I would suggest that you go back to the training ring and get control of the
horse. The bridle is not a stopping device but a signaling device. If your
horse is not capable of being ridden on the trail in a halter it is not
ready to be ridden on the trail!!!
The first thing a horse must learn is WHOA!!! And less is more. The use of
bits, more and more harsh as control is lost, is a very poor excuse for not
taking the time to properly train and condition the horse.
Bob Morris
Morris Endurance Enterprises
Boise, ID