I had a bombed 5.9L in my 07 Ram 3500 before this truck.
Empty, they feel about the same, but the Cummins pulled better. By better, I mean less downshifting on hills. The Hemi has to rev to make power, and it uses more fuel when towing.
That said, I am not at all disappointed with the Hemi. I've posted a few YouTube videos of the truck as well, search ib516 to view them.
The 4.10 ratio adds 3000# to the tow rating and GCWR over the 3.73s. Mine is rated for 15,350# max towing and 22,500#, both of which are higher than my 07 diesel 3500 SRW.