I have always been one to buy end of model year trucks to get the best deal but I have been reading about the new Ford and really like the upgrades made to the 15. I own a Ram and one of the things I always liked best about the Ram/Cummins is the strength of the exhaust break. Apparently Ford is upgrading the Turbo in the 15 and they claim a much stronger exhaust break. That alone would make me go for the 15 as the exhaust breaking I think is one of the best features of a diesel truck, and the previous Ford break was pretty weak IMO. I say go 15.