I don't have pics of the F250, but anyways
With my truck, I've netted 5.5k with my 460, 6k for a pick-up, and 10-12k+ with hay all on the same single tandem 24' G/N several times each. Would I put two 4320s or two 1 tons on it? No, that's just hard on any truck and that's what a semi is for. I'm comparing my truck to a '00 F350 CC DRW and the difference isn't worth 2.5K on the pick-up and 2 more drive tires.
I never notice sway (side to side right?) and the trailer doesn't push me that bad. However, I do like to know it's back there. I've racked up probably 500 miles dragging that G/N and it's a piece of cake to tow. No problems towing that F250 home and I had hills and curves there. I took an easy, banked 90* turn on a 2 lane state highway at 55 and I didn't feel a squirm. A dually isn't worth it to me where I'm at, under 15k net usually. Over 15k, I don't know if I've ever been there, it may be different.