I have had Good Sam ERS for years. If I wasn't happy I would switch, so you know I'm happy. I have also called them out many, many times in all sorts of places and conditions. I have called them to come fix a flat in my own yard probably 3 times over the years on cars as well as RVs. I even called them when my son and I had his car and needed a tow.
We had a blowout coming down Donner Pass (yes, THAT Donner Pass) and the tow guy had to come over 60 miles to help us. That was one time that having a toad was a real necessity - no cell service there! My DH had to drive almost 30 miles to the nearest phone to call ERS!
Another time the rig went totally dead in a parking lot, facing in toward a fence and rig was front wheel drive which would make for intereting towing problems. Of course we checked battery, fuses, wires, connections, etc. before calling ERS. The first guy who came out had a small tow truck and we started getting disgusted because we had specified when we called that we had a motorhome. No way was he going to be able to tow us. Actually, what they did was send someone who might be able to get us started, not tow us. He tried everything he could think of and then called in the bigger gun. Huge tow truck with two mechanics on board. All three guys were like ants crawling in, over, and around. Finally found a hidden ground that was corroded and caused a fuse to almost blow (I say almost because the filiment looked fine). It took them over 2 hrs, but they were 3 of the happiest guys you could find when they got our rig going again! All for the once a year price for membership. Do you know what the going hourly rate for mechanics to work on your rig is?
Moral: GET AN EMERGENCY SERVICE, no matter which one you choose.
Pooker