We debated the same issue when purchasing our retirement combo in 2014.
We opted for: 2014 Ford F250, 6.2L, 4.30 Ratio, 6 speed and a
2014 Cougar (by Keystone) 327 RES. For the amount of towing we do, we could not justify the dually or diesel.(Albeit no argument that dual/diesel would offer a superior performance)
Our two main drivers for our decision were: I)Cost/Benefit II)I love to wash my TV through car washes on a weekly basis. So dually would be problematic.
Some consideration when we factory ordered our TV: 1-Long Box 2- Rear ratio 3- Snow plow package (not that I ever plan on installing a plow but rather to get the beefed up suspension and alternator kit 4- luxury interior as Dear Wife and I travel alone, some creature comfort in the cab is nice. 5- Nice clear coat Ruby Red paint
One regret was that for an added $100.00 we should have ordered the box camper kit, again to beef up suspension.
We have travelled from Toronto, Cnd to Kissimmee, Fl on several occasions and the combo worked fine for us.
Fuel mileage is as expected when pulling 11,300lbs dry.
Hint: As we were in no rush to order our TV we took the time to source out a local dealer/salesman who specialized in bidding on gov't and local commercial vehicle tenders. Reason being he understood what Heavy Duty trucks were about, options and programs.
The salesman was familiar with factory ordering and accustom in dealing with reasonable commission rates, factoring in no lot consignment fees.
Half the battle is being happy and proud as you walk up to your vehicle, then any imperfections don't seem to matter.
Happy trails ...
GPG