I don't know where you saw that the 6.7 has a lot of problems. The only problem I have had was a blown hose on the engine. I have 72K on the truck now and have pulled the truck up and down many mountains out west. There were reports of fuel system problems, mainly people getting water in the fuel and that damaging the fuel system. But I haven't seen anyone complaining about that for over a year now.
The fuel system runs at 25,000-30,000 psi and is very intolerant of water. So that makes changing the water fuel filter very important. Also you should avoid any gas station that is low volume since diesel sitting in tanks picks up water.
But other than those few reports I haven't seen any other systemic complaints.
