Don't know this to be a fact, but........
the guys at work claim when the ford man dropped off the 3 new 450's, he was talking very highly of them except for that the manufacture rated tear down on the engine was at 150,000

I haven't dug into the facts, just hearsay...but might be worth looking into. Another guy traded his in cuz he said the maintenance was costing him a couple hundred every oil change???
Worst thing Ford ever did was try to radical of a change when the "Diesel Wars" started, and then got pissed with International and built their own. The verdict will be out for a long time (or maybe not) on the new Ford diesels, cuz there's still plenty of the good ol 7.3's runnin around. I know I love mine!