We have the RVI system. Tow a Subaru Crosstrek behind our Lexi. I have had it about a year and 6000 miles on it now.
Although I have nothing to compare it too as it's the first brake system I've had, it is trouble free, and once the initial set up is done, takes less than a minute to hook up and 30 seconds or less to un-hook.
I did a lot of reading of posts on 3 web sites, and compared all the available "removable" systems, and choose the RVI. It seems to be the most compact, reliable system, and the few questions I had were answered quickly by the RVI people.
Also bought the RVI Towed Battery Charger and the RVI direct power plug. Whole set up, including the break-a-way took me about an hour to hook up, and most of that time was spent routing the wireing the way I wanted.
Nice system, a bit pricey, but you get what you pay for. Would buy again in a heartbeat.