I had two friends that had Ford V10's.  Both drive diesels now.  One bought a  Dodge and says he is shifting up now where his V10 was shifting down.   Ford's 6.0 was a lemon.  Just saw last week that to overhaul the engine, they have to remove the truck cab!!

I think the Dodge is clearly the best diesel, but I drive a Duramax.  It has been trouble free but sure won't get more than 18MPG ,  We bought it because of the ride and the allison transmission.