The short length of the regular cab, and the tight turning radius of the F450, makes this truck really easy to drive. My thought was with the camper off, I have plenty of storage in the bed, and with buying a big camper anyway, I should have plenty of storage with the camper on. Lining the truck up to put the camper on should be much easier, and hence using the truck as a separate vehicle will be less of a hassle. Also, I have a little extra payload by eliminating the back seat.
Frankly I am a little surprised more people do not go this route. I realize the camper will look a little funny with the cabover extending so far over the cab. But I have never been accused of worrying about looks, at the expense of comfort.