I have a Tekonsha Voyager here too. Took it out to put the Prodigy in. It's ok, but our love of towing 2T or more through forest tracks highlighted its weakness.
The Voyager needs to be set up for the incline that it's going to be working on. This means, if you're spending most of your time on highways in the outback, set it up on level ground and you're good to go (this is what the manual tells you to do). However, on steep gravel descents, its sensor thinks you're already decelerating (because of the nose-down attitude) so as soon as you touch the brake, it gets quite happy with the trailer brakes. We had many a descent with the trailer sliding on us - that gets scary.
I've got it here, Mike, if you want it for a very special price it's yours.