Not an RV but same scenario. I had a flat front end horse trailer and bought the new V nose ones. Here to tell you.....WHAT a DIFFERENCE!
All TT's are like dragging a 4 x 8 sheet of plywood behind you. Even the ones with kinda round corners doesn't make a bit of diff in gas mileage. Like mentioned about making the front aerodynamic takes a big chunk out of the floor plan inside. Something that most if not everyone does not want to give up.
I do think adding one of those air deflectors on top of the TV does help. It made a big difference on towing the flat front horse trailer. Not sure why this is not promoted more for the RV'er.
