2 guys I camp with have 6.0 Ford diesels...One had a preventative "bullet proofing" done on his...Has had no problems...It wasn't cheap but it's done.
Another guy followed the dealer recommendation and basically bought the truck twice with the multi blown head gaskets, blown turbo's etc...The cab has probably been off the truck 5 times in just the past year. Ford didn't stand behind much of anything when this started years ago..I think he got a small check from a class action lawsuit but that didn't help much.
If you find a very knowledgeable diesel mechanic to fix what Ford got wrong before it happens, a 6.0 can be a very good find. I almost bought guy #2's truck last year and was going to send it out..Glad I didn't.