We've used the Vosal on one horse, and he got along great in it.
However, some people have experienced problems with it when trying to
use it on a horse that does not neck-rein very well. The scissor
action under the jaw can be confusing if you are trying to direct rein,
or "plow" rein with it. It should be used similar to a hack or bosal,
in that you use a pull-release action, not constant contact.
There is a distinct art to using each type of bit. The Vosal is no
exception. Play around with it, on the horse - from the ground, pulling
the reins in various directions: separately, together, with "high"
hands, "low" hands, etc., and observe the action it has, and where it
is putting pressure on the horse.
If you can get your horse to work in it, it's great on the trail
because of the absence of the shanks (easier to eat and drink).
Kathy