I carried my Fleetwood 11x TC on a 2007 3500 SRW for a couple years. Then I switched to carrying it on a 2005 Chevy 3500 Dually. The difference in handling, stability, and ride was immediately obvious. The dually was far superior in every way to the SRW. I got exactly the same fuel mileage with both trucks, 10 mpg on diesel. The only real difference in the trucks was the SRW was a regular cab and the dually was a crew cab.
I don't care how many reasons you want to give a dually is the only way to go for a truck camper.
I daily drive my dually. It goes thru bank and restaurant drive thrus a couple times each week. It fits in parking spaces just fine.