Maintenance is a bit of a wash if you do your own oil, fluids and filters changes. Cummins is at 15000 oil change interval. Def fluid is $16 for every 4000 miles or so. Had a diesel, had a hemi, back into a diesel now as tow capacity and fuel economy works out better for me. 2500 is a daily driver and weekend boat warrior......
The 68RFE is no 8 speed zf in terms of smooth shifting but it’s very comfortable on highways between 4,5 and 6th gears.
Pros and cons to each...test drive a warmed up 2500 before making final decision.