Makes me wonder when the RV's will start to be outfitted with 3-4 of the BBQ size tanks. Maybe a stack 2 wide 2 high.
It's not a huge issue finding filling stations but every year they are moving more and more toward the swapping model. I could see this becoming an issue over the next 10-15yrs as the BBQ size takes over more and more of the market, there is less value in maintaining a filling station.
Though I suppose for 95% of RV's a pair of BBQ tanks would be plenty. It's only in cold weather running the furnace where the extra capacity of the 30# tanks comes into play. (big built in tanks on MH are an entirely different matter).