I have a Roadmaster Add a Brake from CW that I absolutely hate. I have used it on a couple of trips in my Jeep Wrangler (2007) and prefer not to use it. I keep it in the coach in case some nice officer makes me install it but my coach and Jeep combined weight do not exceed my coach GVWR of 25900# and, of course, it does not come close to my GCWR of 33000# so I really have no problems stopping both vehicles without using an aux. brake system. I suppose if I were in the mountains it might come in handy but for normal Interstate driving (which is most of my travel), I prefer not to use the brake system.