Originally Posted by indynotch50

Chevy uses almost the exact same turbo as the one on the 6.0 in their isuzu engines. At first there were issues with these turbos but they have all the bugs worked out now, and that's both companies. I'm not sure what line of work you are in using an F550 but cleanliness is an issue. Change your oil often and don't use synthetics. Synthetics will retain some of the dirt particals that would be washed out with normal diesel oils. Synthetics have suspensoin properties that are harmful to the injectors and small sensors on these highly sophisticated engines.
As far as the way of the future, I can see that, however they are a lot heavier and larger than normal turbos, compare the size of a wastegated 7.3 liter turbo to a 6.0 turbo. However the 6.0 turbo will boost higher, all across the board, if they can make them smaller for applications like these evos, you will have no lag, much higher response, and just as good if not better boosting capabilities.
Since you guys are using an F550, I am assuming it's a fleet vehicle. Those are the most troublesome because they are not properly maintained. The other day I saw a guy that was driving an ambulance complaining about performance, he had 11,000 miles on the oil change and the engine mostly sat at idle, i'm shocked it still was even running.
I do know that for the new ford engine by international, the issue of the vgt valve and variable geometry turbo will be fixed.