Just got back from a short vacation with my 2016 2500 MegaCab Cummins I purchased last year. Visited Table Rock State park area in upstate SC. Great towing experience!
Stats, 28' TT, 6500#+/- dry, and maybe 7K wet (we traveled lite), hitch weight around 700# and did use WDH hitch. Listed payload is 1900#, so well within range for DW and myself.
Experience, Averaged around 11.5mpg towing (speed limit or slightly under if 70mph), so did not have to fill up on 300 mile trip with the camper attached. Always used auto exhaust brake. Very stable, only felt sway a couple of times from wind gusts. No problem in mountains with going uphill or down. Also used the two/haul mode when coming down twisting mountain roads, six speed did a great job maintaining speed. Never saw the transmission temp go over 169. Did bounce a little on SC roads...
Previous TV was F150EB with 6.5 bed. Also towed well but mileage was only around 7 or 8, and not quite as stable, but not a 3/4 ton, so shouldn't really compare.
Overall, very happy with new truck. If we upgrade, it will be to a small fifth wheel, but purchased the truck to go west and maybe Alaska in the next few years.