Comparing a 1500 to a 2500 is comparing an apple to an orange. HD trucks, Cummins or Hemi powered whichever flavor you own is a real truck. All of the suspension and steering components are massive compared to a 1500, heck even compared to GMs 2500 for that matter.
Before I bought my ram I crawled all around under all of the trucks and rams suspension and steering components were the biggest/heaviest. Fords was heavy too, but not like ram. GMs still used IFS, junk on an 2500 HD truck in my opinion.
To me, personally, my 2500/6 speed/ 3.73 geared beast is a whole lot faster and quicker than that 7,000 brick has any right to be. I am sure the new 8 speed trucks even more so. The fact that the 2500 "didn't feel more powerful" upfront is really impressive in and of itself. 1500s are 70s full size sedans with beds on them in terms of size of suspension and steering components. 2500 on up is a whole nother league.
Nothing at all wrong with a 1500, I've had many and they have their place, but I love my Ram 2500HD. Best truck I've ever owned.