the main difference I noticed is the stopping distance.
I plan on moving up to the 3500 for the stability and braking.
3/4 and 1 ton trucks have the same brakes from the factory, even the duallies. Difference between them is spring rates and the sticker on the door that says you can carry more weight, and if it's a dually vs SWR you get a few more square inches of tire contact patch on the ground. I do like the stability and handeling of a dually and the fact that I have 3 spare tires if I ever had that bad of a day and have to single out.
The longer braking distance is simply due to the increased weight of the larger unit. Purely the phyisics of the weight, speed, total tire contact patch and road conditions. That's whay it takes an 80,000 lb semi truck about 350' (that's 50' longer than a football field) to stop at 60 mph on dry pavement vs 140' for a Honda Civic and other similar cars.
Increased following distances when towing is a must, not an option.
Go to a junk yard that specializes in 3/4 and 1 ton pickups. Usually hard to find good front end parts but you can get all the rear bumpers and tailgates you want.
Stay safe