I have to respectfully disagree with Cumminz on his point of cab removal not being an issue because he doesn't turn bolts. The point to consider is if you did have to have major work done its going to be extremely expensive. Up here the diesel rate at a dealer is at least 135/hour. Flat rate on a duramax head gasket or 6. 0 is around 34-38 hours. Cummins is about 9 ish. Add in the extra parts (2 head gaskets instead of 1, reusable headbolts on a Cummins, not a Ford etc) and the costs become huge. After warranty costs are a significant influence in a purchase, especially if it were to be be my retirement truck.
That's what I love and appreciate about Dodge with a Cummins inline six cylinder. Plus they're reliable.