we never rented, but my gf owns a 30-ft pull behind camper. its pretty great for vacationing and id encourage you to give it a shot. weve stayed at some state parks, KOAs and private parks. I would reiterate what someone else said: read reviews.
Also: google earth the place and see what the layout is like. The KOA asheville is beautiful, but very cramped and not private. People park in a string and you cannot get away from them.
KOA hatteras, though, people park parallel so there is privacy between your camper and the others.
It's pretty great staying at a park with a view, or thats within walking distance of swimming, fishing, walking trails, etc. I don't think its worth the trouble using an RV or camper if you cannot walk out of it into something you can immediately enjoy.