You can likely tune the MDS off using alfaobd, a tazer or custom tunes. I've been able to on basically every truck I've owned. If I were planning on keeping the vehicle forever I'd prob do an MDS delete kit at some point to remove a potential failure point, but I'm unsure if the newer systems are as much issue as the early systems, I expect not in which case I'd run them till they died.
I've got a 2019 CCSB 2500 CTD. I love the thing and most everything about it, although I do have a few gripes.
- The AC is terrible (there is a recall for my year, I've not done it since I'm waiting for the CP4 recall to get parts in)
- The CP4 is a ticking time bomb (obviously not an issue on the HEMI)
- There are some polish/QA items I've been less than impressed with, but I'd still take the interior cab to any of the others.
- I wish pano roof was an option. It's one of the biggest things I wanted. I'd risk the leaks to have it.
- Full flat rear floor would be awesome. I keep the rear seats up almost all the time, the little storage compartments below are functionally useless to me because of the layout of the whole thing, it's just a poor setup. You have to fold the "flat floor" panels to access the little boxes or storage, and it's a pain, so I don't keep anything in there that I need to access remotely frequently or quickly.
- A slightly larger cab would be nice, the Ford SD line had so much room, way more than the Ram trucks and it's not even close.
- Wish I would get a 37" spare under the bed (although to be fair, as soon as I could get a 37" in there I'd be wishing I could get a 39", then a 40", so on…)
Overall though, I'm pleased with the truck. Cummins will last me "forever", assuming the body doesn't rot away. The engine is a simple design, I like the simplicity of the 68rfe, and have planned the money for the trans build once it blows. Plenty of additional power options available. Easily tows my 32' trailer on 37s while getting better than expected milage. I can add an extra fuel tank, or expand the current one. Aftermarket support for these trucks is awesome. I really enjoy a lot of the AEV designs for bumpers and flares, and the other companies like chassis unlimited and expedition one make some nice looking options as well.
Plus, it just looks great. I do really love the exterior design of the 4th gen trucks, but I think the 4.5 looks awesome as well, just great proportions overall, and the turning radius isn't absolutely awful. Sometimes I wish I went with the megacab for the rear seat space (2 dogs, 1 kiddo and another 1-2 planned) but I think we will survive just fine. We did trips in a mercedes station wagon when I was young, so kids can suck it up with heated rear seats.
I think there will always be something else, something better, cooler, different, that is out there, but I'm a huge fan of having the diesel truck and plan to continue building mine as time, and funds, allow.