In the past five years, I've owned a 2020 F350 Lariat power stroke, a 2020 Silverado 3500 LT duramax, a 2022 GMC Sierra 3500 DRW Duramax Denali, a 2024 Silverado 3500 duramax high country, and now a 2024 Ram 3500 Hemi tradesman dually.
The most comfortable truck in my opinion was the GMC Denali dually. The leather quality is substantially better than the Chevy trucks of those years. Given, by 2022 the cab design of the T1 platform GM trucks felt a bit "aged" compared to what Ram and Ford were offering, but we liked it. Simple and clean, smaller center stack screen, knobs for everything, the gauge cluster still had analog tach/speedo (with a smaller digital center screen)
That truck rode great, towed our Alliance Paradigm fifth wheel trailer really well.
The least comfortable truck was the 2024 Silverado 3500 high country. GM must've changed seat foam suppliers or something, because both my wife and I decided after two trips in the truck that the seats were absolute torture on long trips. We tend to drive 8 hours on travel days, and the Chevy seats caused nerve pain for both of us.
One thing I can say was universal about every GM duramax I've owned - they were all DOGS off the line. "Duramax dead pedal" is a very common talked about issue. I got rid of the GMC dually because we lived in Bend Oregon (de-facto roundabout capital of the world) and timing merges into roundabouts with that truck was downright scary. No amount of skinny pedal application would make that truck move faster than it decided it wanted to go. Banks pedal commander helped, but it was still frustrating.
Part of trading in the 2024 chevy so soon was 'compromise' on the trim level of the new truck (per the wife/CFO) We both really wanted to try a gas rig out to try and save the initial $10k investment up front (and 50 cents more expensive diesel out here) I would've liked a few more creature comforts, like dual climate control and heated seats. The dealers in western Washington simply do not stock order Hemi trucks in anything above tradesman trim. With the rebates going on now, we decided not to order a Hemi bighorn and settle for Tradesman.
I can say after three long trips, the seats in the tradesman ram are an order of magnitude better than the chevy high country seats. They don't have heat/ventilation, but the seat foam is more comfortable, the angle of the seat is better, and the vinyl handles three dogs of filth really well.
The only thing I can say about the Ford was the axle tube crushing issue gave me extreme paranoia - we towed around 14k on a fifth wheel, and my rear axle weight was within 500 lbs of rating. Ford/Dana decided to start making thinner/tapered axle tubes on the F350 starting in 2020 - and didn't weld the spring perches fully. So the axle tubes were getting crushed. The recall for that had the Ford dealers welding the perches on. My wife said she wouldn't ride in the truck anymore after that. I felt the overall truck interior/exterior felt the most dated of them all...