Come on Hook-em, help a fellow Texan out-- I know you probably know this stuff
The advantage to the MD vs the 3500 has always been the load carrying capacity. Not so much in trailering. In fact, based on their published specs, many times it has less towing capacity than the 3500, but it will handle a much higher pin weight. Of which, the two go hand in hand.
Depending on what rear end/trans you choose, looking at the spec sheet for the MD, it shows GVWR of 15k / 16k / 16.5k
with a GCWR of only 26k / 30k
I suspect that 30k combined is NOT with the 4:30 rear you drove.
You're projected empty weight of 11k, only leaves 15k / 19k for a trailer...per the specs, towing less than the 3500.
It's not the same motor in the MD as the 3500....several things are different; turbo, lesser tuning output, etc.
As well as a different transmission too (depending on your option selected).
It's designed to get the load moving off the line.
Which is what the 2020 3500 is claiming with the 10-spd paired with the 3:42(?) rear vs the std 3:73 for the last 19 years....getting the load moving with ease.
2007 LBZ 3500 LT3 DRW Crew Cab, Sulastics, Putnam XDR 15K, B&W 30K-Turnover GN+Companion, Ride-Rite Air...EFI'd by Rob
2008 LMM 3500WT DRW Crew Cab, 8 'Flat/GN, Workforce Alum Toolbox, Ride-Rite Air Use-ta Haves 2006-6.0 3500 WT DRW ExCab Flatbed, 2005-LLY 3500 LS DRW Crew Cab, 2002-LB7 3500 LS DRW Crew Cab I Live my life in such a way that when my feet hit the floor in the morning...Satan shudders & says "Oh shit, he's awake!"