I used a Ready Brute (tow bar with included Ready Brake) system for years and would do so again in a heartbeat, if I had a MH again. The older I get, the more I realize that, as wonderful as computers and electronics are, they are prone to arcane failures that I don't understand or know how to fix. Mechanical stuff I can understand (and often fix) when it goes wrong. I guess I live by the K.I.S.S. philosophy.
I have never tried Brake Buddy or any of the others of that ilk. I am sure they are good. When I bought my Ready Brute system, it was noticeably less costly than the other systems, and it just made sense to me. I installed it myself, and it performed flawlessly, even in a few panic stop situations.