From experience I went from a Dodge3/4 ton 4x2 to a Dodge 1ton dually. I found the dually to be more stable in the fact that when I crossed a expansion joint or gap in the roadway the rear of the truck did not feel soft or "unstable". If I had smaller unit I would have stuck with the 3/4ton truck.
Another thing is if you ever experience a blowout or flat on the SRW on the rear while towing you will be greatful for the extra stability on he DRW. To each his own choice would my 3/4 pull and stop my rig yes....do I pay more for less mpg and the extras tires on my dually yes is it worth it to me yes when I have the kids and other half in the truck on a trip that little piece of mind is important . I have towed all over the country and parts of Canada and Mexico with both trucks and I have yet to regret moving on up to the DRW truck it even makes a difference when towing my flat utlity trailer with equipment or what ever on that trailer and it is a bumper pull trailer
Hope this helps, if you have a friend who has DRW give it a test drive and see how it feels to you then go from there with your choice