I just looked this up, the 5.2L Magnum makes torque upto 3000 rpm, pretty flat, but then it drops off badly. The V6 Pentastar makes 90% of full rated torque from 1800 rpm to 6350 rpm, because it has variable cam timing ( sort of like a Honda with VVT ).
I have to agree with everything else you said, stiffer frame, bigger brakes, more weight. That all makes so much sense.. My buddy built a street rod, with a 454 motor. It scared the "heck" out of me, you could feel everything flexing whenever he stepped on it, or braked for a corner..
The V6 has 8 speed, the V8 has 4, but in tow mode, the V8 has 3 speeds, and the V6 will likely have 6 speeds.. They both have the same rear gears, 3.55, but the V6 new truck will have 18" tires, not 16". I expect the V6 to run at a slower speed than the V8.
Humm, its food for thought, I have driven in a few 2500 trucks, and they feel so much more solid than a 1500, even when not towing.
Thanks for your comments