Congratulations, I made a similar switch to a 2004.5 model.
My son bought the same truck new with the 6.7 and DPF except 4WD. The engine was strong enough and reliable although he had a lot of emission codes. He did have to replace an intake heating grid. His fuel economy was poor and he was not happy about it. Once his warranty ran out at 100k he had all the emission stuff removed or bypassed and with a mild chip or flash installed. The engine came alive, more response, more power and almost double the fuel economy. You couldn't pry it away from him now.
I've heard you have to run them hard to keep the DPF clean.
75k now should enable you to drive that truck for a lot of years. Enjoy.