My experience with the truck in question is pretty much the same as the others here - more than adequate for my 8500# TT even in the hills. I came from a diesel and while the Hemi isn't quite the hauler it's close enough for what I need.
MPG is 13-14 as a DD with lots of city mixed in. Highway could be as high as 18-20 if I would keep my foot out of it and stay at 55-60. Towing is anywhere between 7-10 depending on the terrain.
I ran into the same issue with the gearing when I purchased. 373 was easy to find, 410 very difficult. For mid sized load the lower ratio is fine. I just can't imagine the difference is as much as everyone makes of it but w/o driving them back to back with the same load I can't say for sure.