If you really want a GM then keep looking, when I shopped I looked at all 3 they were similar in price/options. This is my 3rd ford, previous being a 2011 6.7 F250 had over 120k miles never seen a dealer. There were some internet complaints about earlier model pumps and a few engines, but I never have seen one in person.
I didn't buy a Ram because I question them already knowing out of the gate that they need to offer a better transmission.
Any of the 3 should do what you need, none are bullet proof!