Electric or surge brakes - What are the considerations?

I used to have a Master Tow dolly with surge brake. It worked very well. For gentle stops, the motorhome brakes do most of the work. If you need to apply the brakes hard, the surge brakes activate and you can definitely feel the difference. Electric brakes would require a 7 pin connection instead of a 4 pin connection and would require a brake controller be installed in the MH.