After reading several horror stories about campground power and the terrible things it can do to your Roadtrek electronics, we decided to buy a 30 amp surge protector from Camping World. I went with the portable one designed for outside use. The permanently installed inside one would be nice, but I didn't want the extra work of installing it. I plug the surge suppressor into the end of the "fixed" extension cord on the Roadtrek. This cord I leave curled up inside the storage compartment, together with the surge suppressor. I have a separate 25' cord rated for 30 amps that I use on a day-to-day basis. I plug this into the campground power receptacle and plug the other end into the surge suppressor (which stays in the storage compartment).
I find I just can't bring myself to leave the surge suppressor outside by the campground power post as the instructions say. It's too expensive to leave lying around like that. I do find that it's too much of a hassle to feed the power cord through the little hole (by the city water inlet). I just let the cord hang down from the storage compartment door, which I don't shut quite all the way.
The surge suppressor is very nice. There is a two minute delay between when you plug the power into in and when it lets the power into the Roadtrek. This is to protect the AC unit if the power goes out for a few seconds. Lights on the unit let you know if the campground power source is wired incorrectly or is over or under voltage.