Speaking from the Ram/Dodge side point of view if you're considering one, the towing capacity between a 1 ton and 3/4 ton crew cab/swb is 40 lbs. Yes, 40lbs in favor of the 1 ton. In mega cab/swb form it's 90 lbs. In crew cab/lwb it is 120 lbs in favor of the 3/4 ton, unless you get the heavier duty Aisin transmission then it is significantly more for the 1 ton. So take that for what it's worth..
Unloaded ride quality, in years 10, 11, 12, & early build 13 the empty ride quality between the two was virtually the same. Both 2500 & 3500 had leaf spring rear ends, 3500 simply had overload springs as well. 14 and newer the 3/4 ton has a lot more forgiving ride quality while empty due to a coil spring rear end, where as the 1 ton still has the leaf springs. Even with the coil springs it still feels like a heavy duty truck, but doesn't buck over bumps nearly as bad as an empty leaf spring rear end.
When loaded I haven't noticed any squat or sag difference between the coil spring rear and the leaf springs.
This info I have from my own experience and the attached Ram towing chart for current year pickups. I get a new pickup every year or so and have owned a 10- 2500, 11- 3500, 12- 2500, currently own a 13- 3500 and a 15- 2500. All in crew/swb or mega/swb form. I can't speak for crew/lwb versions.