Be very sure you want such a big thing.
Reconsider getting the smallest TC you can live with.
Have you looked at the Big Foot and other fiberglass shell campers?
Big and roomy and having too much storage space is nice, but you pay for that on the other end. Lots of storage means you will not find that thing until you go to sell the camper and clean it out..
Big means more difficult to handle, drive, park and all these things compound themselves when towing, towing anything big or small.
You will need to expect some blowouts of tires, though dually less than single.
mpg? haha, you cannot even think about that at this point.
Backing up a trailer is no fun. Is the pontoon wide enough you can see it in the mirrors? (I have a trailer so narrow that I cannot see it until is almost jack-knifes).
But you will have pontoon no matter what…
Are you a couple that lives inside or that sits outside and just sleeps and cooks inside?
Except when stuck inside on bad weather days, consider that inside is just the base station for being outside…
The bigger that camper is the less likely you are to just pop it on and go for a trip according to opinions of some owners. or will you leave it on all year???