What I am trying to say is that the lower mpg I am getting (about 25% less than my last 5.9L Cummins), is cost neutral for me & where I live, due to the fuel cost delta. I am happy about that.
I'm not trying to convince anyone that their choice of tow vehicle is "wrong", just that I am very happy with the choice I made, and if given the chance to go back and make the choice again, I would choose the 6.4L Hemi. It suits my needs perfectly.
It does a great job with my RV, has been 100% reliable (yes, it is still new), and provides something my Cummins rarely could....HEAT! :)