For some, Dodge/Ram has had a spotty reputation for overall reliability, fit, and finish, through the years. However, in the last few years Ram has really ramped up their game and increased their marketshare against Ford, and especially, Chevy. IMO, this is due to much improved quality and performance. Arguably, the Cummins is the most time-proven design of all the Big 3, 3/4 - 1 ton diesels.
Ford has had some interesting growing pains in the last 20 years with their Power Stroke Diesel. Some seem to think Ford may have finally found their time-proven design with their latest iteration, the 6.7 PSD. Only time and some proof will tell.
Chevy Duramax? Well, not much controversy here, which is both, good . . . and, maybe a little boring.