Yeah you opened a good one, because there are many different systems, and most have fans who prefer them. Ill just tell you mine and why:
First, I like air powered systems because the provide exactly proportional and also immediate braking. No lag time for actualtion and release, and no over or under braking, no adjusting - however hard or easy you brake in the coach is how hard or easy your toad will brake.
Second I like the M&G Engineering system because there is nothing to set up for towing, or remove and store for driving the toad. The actuator is under the hood and all you have to hook up is an air line and tail lights.
So on the lights, the systems that push in your brake pedal will turn on your brake lights. Thats a nice bit of simplicity but the trade off is installing and removing the ram that attaches to the brake pedal. And it doesn't cover tail lights - you need power for that or you’ll run your battery down.
I just ran a four wire trailer light cable from the flat four (or adapted round 7) on the coach to the flat four on toad (jeep in my case). So when I hook up, I have an air line, a taillight/brake lights line, and my two safety cables. The key to the jeep doesnt have to be on and the jeep doesnt need power, so I dont need to run a hot to the jeep battery and the battery will not go dead. Power comes from the coach tail lights and brake lights.
The downside to the M&G system is the initial install. It does take some wrenchly know-how, and it may require some rearranging around your master cylinder as it moves the master cylinder forward about 4.5” from your brake booster. And of course you need that air line to the rear of the coach - if yours doesnt have one, thats one more expense/chore.
So as you can see this system is not for everyone, but I prefer it because once its installed, you never have to think about it again. The only thing you're doing for brakes is connecting an air hose and taillights. Hope this helps.
