I'm not sure which Roadmaster braking system you're talking abot. The ones listed on the Roadmaster website (www.roadmasterinc.com
) are as follows in order from the most sophisticated to the least.
Automatic progressive system that can be used on vehicles with "active braking systems"
9060 for hydraulic brakes, 9100 for air or air over hydralic brakes. There are a cuople variations of each with and without breakaway systems.
"brake in the box system" with proportional braking.
"brake in the box system" with 3 preset braking levels.
We use the Brakemaster 9060 because we have a gas powered coach with hydraulic brakes. It's a truely proportional system in that the brakes in the towed vehicle are applied at the same rate as those in the motorhome. It's a great system and takes only a few seconds to connect and disconnect.
One reason we chose this system is that the activating cylinder is relatively small (compared to a "brake in the box system"). It doesn't take up much storage room when not in use, which is important when you drive a Jeep Wrangler TJ. Another reason is that the plumbing on the compressor can be modified to use the compressor for inflating items including tires.
The compressor and proportioning valve are permanently monted in the motorhome. The activating cylinder is mounted in the towed car only wjen the system is in use.
If we had it to do all over again we would purchase the same system. It's dpendable, versatile, and easy to use. The initial installation takes a while, but it's time well spent.
ON EDIT: I looked up the 8800 Add a Brake system and it appears to be an obsolete (as in no longer in the current prodct lineup) version of the 9700 braking system. If I'm correct that would make it on the low end of the prodct lineup with all others available being more sophisticated.