We used a RoadMaster 2000-1 for around 20,000 miles towing a Buick LeSabre. We liked the electric brakes because they would hold when stopped going uphill while the surge brakes won't.
If you have a motorhome built on a Ford chassis a brake controller is a plug and play device. We used a Tekonsha P2 controller.
The P2 for all intents and purposes has been replaced by the P3. Also the 2000-1 dolly is no longer manufactured. It was a great dolly, in fact the one we purchased in 2001 is still being used by a friend to this day. I think their demise was mainly due to cost. Shortly before they were phased out the retail price was in the $3,700.00 range. There are a lot of dollies on the market for a lot less money'
RoadMaster currently makes a dolly with a swivel plate. The original 2000-1 had steerable wheels that would follow in the tracks of the rear wheels on the motorhome.
Tweety's still offers the original model for a little over $3,800.00.
https://tweetys.com/roadmaster-2000-1-premium-adjustable-tow-dolly-with-self-steering-wheels-and-electric-brakes.aspx
As an FYI we stopped using the dolly in about 2005. It seemed pointless to tow the Buick half way across the country, then park it in the campground when we rented a jeep for off roading. Often times the Buick got 20 miles or less on the odometer over the course of a 2 week trip. In 2005 we purchased a Jeep Wrangler that we still tow 4 down today.