I have the exact same engine/tranny setup in a 2018 tradesman. Like you, I bought it as my "last truck forever" setup since I'm getting up there in years and am on a fixed income. I chose that setup because of its reliability, durability, and knowledge that if I just stayed on top of the maintenance, I will never need to visit a dealer again.
As for the rest of the truck, well...it's my 5th Dodge/Ram and I've come to expect some of the little things going wrong. This version seems to be much better in that regard, but it still has had a few issues--a bad wheel speed sensor (common) and a defective parking brake assembly (uncommon). I also had to replace the egr filter and clean the assembly at 50k instead of the recommended 67k (probably a result of having the HO version of the CTD). You have to drain and fill the fluid on the Aisin every 30k, with a pan drop and filter replacement every 60k--but that's relatively easy to do. That's the price for having the strongest transmission on the market I suppose.
A few tips--change the fuel filter/water separator yourself and you'll save about $300 in labor costs. It's easy once you learn how to do it. Also, get used to always using your full exhaust brake. Soot on the turbo actuator and vanes tends to build up over time and you can end up having to replace the whole thing for a pretty expensive price. Once you get used to driving that way, you'll wish all of your vehicles had an engine brake. I saw a post from a hot shotter a while back with 300k on his Cummins who said he has yet to replace his brakes (or his turbo) because of using the engine brake, so it saves you time and money as well.
