I’ve looked at the duromaxes and would love one, but I don’t have the funds for it.My prior 95 Suburban C2500 had the 7.4L and 4.10 gears with 4L80E trans. It was a great combo of family + towing rig (which is what I used it for) for its era, and did relatively well with our 32’ RV trailer weighing around 9500# loaded. Tongue weight was around 1300# and the Burb barely squatted at all. I did have a weight distribution hitch and airbags also to balance weight and smooth out the ride, but didn’t really need it for leveling. I’d imagine you could expect the same from a pickup of the same setup.
All that to say… now I have a 2005 Duramax CCLB DRW and I don’t think I’ll ever go back! It tows like there’s nothing behind it.