I have a 2005 Saturn Vue and I just ordered the ReadyBrake system to attach to my existing Demco tow bar. I've been using the Brake Buddy but found it awkward at best and every once in awhile it would turn off probably because the toad battery would draw down.
Just be advised, I love the Saturn, but the whole front end assembly is plastic and styrofoam. Make sure your installer securely mounts the baseplate to solid surfaces. Mine didn't, the car broke free at a very slow speed, with no damage to others, but the installing shop was responsible for major body repair to make everything look new again. (They accepted full responsibility).
I've been researching the Ready Brake system for a month now, and I think it will be a good choice.