Tow vehicle and everyday driveability question

Let's see.. 99% of my driving is not towing.... So the decision was easy to me. My truck pulls my trailer just dandy and it doesn't ride like a lumber wagon empty. The 19 mpg I get empty on the road far surpasses my sons HD 2500.

I ride in a 2003 Chevy HD 2500 all the time and it does not ride like my puny little F-150 nor does it get the gas mileage.... Maybe in the newer HD 2500's it's different, but it isn't in a 2003.