I met lots of RV'ers at a show I went to in Pitts. First RV show I've been at. Everyone friendly. Same with RV'ers on the road. But I boondock and seldom go to campsites. RV'ers seem pretty nice from my limited experience over the last 2 decades. But I don't hang with them, busy working. Just short chats.
Was working in NYC and had to camp in Jersey City. They had a mini Airstream convection. Talked with tons of Airstreamers. Everyone friendly. Some seem to look down on regular campers, but in a joking way, not mean or prejudicial.
BTW, I'd say a full timers is someone that lives in their RV year round that has no house or apartment. But it does not matter how tight the definition is.