I have the Garmin 760 RV and doubt I'd buy it again. Mine has given poor routing and it has been flaky. The specified RV routing has not been reliable enough for me to trust-such as road selection based on RV height and size. The RV park database has been useful at times.
If I was doing it over, I'd just get a standard smaller GPS from Garmin or Tom Tom-prices a little under $150 at Costco-and not waste the money on the RV model. Use this in conjunction with smartphone Google maps (when you have service). Google maps is probably the best single navigator I've used. It is always a good idea to carry paper maps too.