There is no truly RV specific GPS. The routing will not allow you to set RV specific routing options and may tell you to avoid roads you are allowed on or send you on roads many RVers would avoid. There's really no way around that so be sure you use good judgement and plan your route before you go.
I still prefer the Garmin brand and I can add any POI groups that I like. Since I already know which campground I am heading for before I leave, having a campground data base is of no value to me.
I recently updated from a 2720 I bought in 2005 (it's now in my toad) to a 2797 (2013 series) and really love the large 7" screen and voice commands and lifetime maps and traffic.