Sprinter engine reliability?

I am interested in a Sprinter type motor home but wonder how reliable the Sprinter really is. Current Diesel engines are not as reliable as they used to be. The Sprinter has a complicated, small 3-liter turbo charged, after cooled engine that needs DEF fluid and pushes an 11000-pound van. I just bought a new 2500 Ram Diesel Truck to pull an Airstream Trailer. This was a mistake, I really don't want to have a long rig or pull anything behind me. I want to get a class B camper like an Interstate or Roadtrek. Non Extended. I have a sour taste with Mercedes Diesels, because I once owned a 300SDL Diesel and it was the worst car I ever owned with tons of engine problems.

I like to ask Interstate owners about how many miles they put on their camper and what kind of possible Sprinter related problems they encountered. Are you concerned about not finding a Sprinter Dealer for repairs when you are on the road? At 73, I want to retire and drive with my wife around the US in a reliable camper.

Thanks, Gerhard