RAM had there act pretty well worked out by 2015. We have put 20K on out 2015 3500 Laramie SRW SB 4x4 and it has not yet had to go back the the dealer for service. Knock on wood. We love the truck and the Aisin HD tranny that we optioned for. The Aisin has lower 1st and 2nd gears compared to the RAM 68RFE tranny to get a load moving with the tall 3.42 gears. It is a freeway cruiser empty and tows our 16K fifth wheel very well in 5th gear at 60 MPH and 1700 RPM.
Only thing I would change is a bit larger fuel tank.
We got into 40 MPH side and head winds in Nevada and it handle our 39'4" full high profile 5th wheel without getting pushed around. Click Our Rig in signature Chris