I sold my '11 F450 just recently. But that was because we sold the Cyclone as well and I really didn't need a dually anymore. The guy wanted both truck and camper so who am I to stop him. :B
But that being said, I was more than pleased with my 6.7. Had it over two years and 20,000 miles and it was perfect. I also had an auxiliary tank which some say invites water into the fuel. Never an issue.
Some extra notes though. I always had my Ford dealer service the vehicle, used PM-22 at every tankful, and always bought fuel at popular outlets where the fuel stayed fresh.
When its time to buy another diesel, it'll be at the top of my list. My opinion is the whole HPFP thing is not as big as it is made out to be on forums. Best of luck.