My 6.0 is 7 years old and still fine.
I do plan to replace the egr cooler sometime in the future. Not because it's failing but because it's a known failure point. However, I do run Powerservice's Diesel Kleen year round and run synthetic oil to protect the injectors as well. The variable vane turbo is very cool, but is subject to rust if you don't drive it.
However, I did my homework by visiting Fordtrucks.com before I bought mine. If you buy a complex truck which includes all of the newer diesels, and don't look into the potential issues, you are likely to hit issues. Afterall, they aren't a gasoline engine.