Initial update:
We have now traveled to our campground destination.
Approximately 270 miles mixed with highway (roughly 200 miles) and the remaining small towns and 2 lane secondary roads with plenty of hills and curves heading into the Catskills in New York.
I've loosely attempted to follow the manufacturers towing break in procedure which states not to exceed 50 MPH for the first 500 towing miles. As those recommendations cover every gas truck from a 1/2 ton V6 to a one ton crew cab dually with no regard to gear ratio, tire size or trailer weight or load on the tongue, I'd say I could deviate slightly and kept it around 55. Once broke in I typical keep it around 65 on the highway. I'll be curious to see if the extra 10 MPH makes much difference.
So far, the truck averaged 10.5 MPG on the highway and dipped to 9.7 in the hills (averaged in with the highway). The 1/2 ton was around 8.9 to 9.1, but at 65 MPH, so we will see, but so far happy with that.
Power wise the truck seems to handle the hills much better and additionally seems to be more effective at engine braking, though that is seat of the pants.
Actual braking seems better as well as it seems to stop much shorter and the built in brake controller (the 1/2 ton did not have that) is buttery smooth.
Most important, on the road the truck is much more composed and confident feeling. While the 1/2 ton did a fine job for what it was, it felt a bit too much like the tail wagging the dog, where the 3/4 does not feel that way. It feels more planted, not tending to wander or feel like it was getting pushed around as much. For what it's worth, as a passenger, my wife said it feels more comfortable to her, not feeling the sway.
I will offer more updates in a few days when we travel back.