This is not a gas vs. diesel thread and is not intended to go in that direction. This is simply my my own experience.
I picked up the Eagle HT yesterday at the dealership, which is about 70 miles from my home. The trailer weighs 8449 empty, which is of course how I pulled it. My truck is a 2017 f350 long bed with the 6.2 gas engine. My hitch is a PullRite SuperLite that is basically the opposite configuration of an Andersen Ultimate with the ball clamped to the kingpin. I have never in my life backed a 5th wheel up, having had a travel trailer to this point.
First, hitching is a breeze. I dropped the tailgate, aimed the center of the truck for the ball, and backed up until the spotter told me the ball was within the bed. He put up the tailgate and guided me back until the ball was over the receiver and we just lowered the ball. It could not have been easier.
Since I have no 5th wheel experience I left the dealership and went to a nearby abandoned grocery store parking lot where I practiced backing up for a half hour or so. It wasn't nearly as difficult as I though it would be - just have to remember which way to turn the wheel. I found an internet article by Michigan Traveler and I highly recommend it for first-timers. Here is the link:
For the drive home I had about 15 miles of interstate-type road, followed by several miles of two-lane winding rolling hills leading to a 4 mile steady 7% climb. At the top of that mountain are 5 miles of up-and-down short steep hills and then a 2 mile 7% grade dropping into a small town. The remainder of the ride is uneventful typical Pennsylvania back roads with the exception of a very steep 1 mile hill leading up to where we live.
The truck/trailer/hitch set-up is unbelievably solid. There was no buck-and-chuck, no sway, nothing. It felt like the Eagle was part of the truck. The folks on here who say it's much easier to tow a fiver than it is a trailer are underselling that point - it's like night and day. The gas engine pulled very well. I was a little apprehensive (actually very apprehensive) coming up to that 4 mile climb but I was able to comfortably maintain 58-62 mph in 3rd gear the whole way. I kept the rpm's at 3500 so the V8 was growling but was not screaming by any means. There was a lot of upshifting and downshifting through the hills but that did not bother me. The long descent into the town was not a problem - I just locked out the top three gears and used the brake judiciously. I would imagine the 6.7 powerstroke would be better overall but the 6.2 did just fine.
I had two choices getting the trailer into my driveway: pulling in head-on and turning it around in the front field, or backing in from the road. I chose to back in just to see if I could do it. Because of the angle and narrowness of the driveway it's not a straight-forward process but I managed to do it in about 10 minutes.
The purpose of this too-long post is just to pass along my experience to anyone who's on the fence or concerned about the gas/diesel or 5th wheel/bumper pull questions. I'm not offering any opinions, just saying how things went for me, and if you've read this far you deserve some sort of medal