I do not own a 6.0L PSD, but my neighbor does, and he's seen the gamut of the reported 6.0 problems including turbo vanes stuck, EGR cooler issues and oil cooler blockage, etc.
After much review, he and I are of the impression that the root cause is the oil cooler passages being too small, as roadrunner1 has stated. These coolers become blocked with debris. This causes a domino effect in reducing coolant flow, which overheats the oil (affects turbo, injectors, etc) and also the EGR cooler (affects the cooling system by overheating it, and ultimately burping coolant out the tank and/or blowing head gaskets). It's not a question of "if" this will happen, but "when" it will happen. In short, the oil cooler will become blocked, which makes for low coolant flow, and hot oil.
My neighbor went through 2 partial turbo replacements, one full turbo replacement, the EGR cooler was upgraded with an aftermarket item, and finally a new oil cooler was installed. Ironically, a simple coolant bypass filter would probably stop all this from happening. He found a nice kit on-line, but one could piece it together from scratch. Plenty of options out there.
This oil overheating condition often creates these subsequent mechanical issues, and then the oil gets blamed ... How many times have we seen some brand lambasted for a perception of poor performance, when the oil is not the root cause? You could choose to run synthetics, but it would only serve to delay some problems (not stop them) and it would not even address others.
Another problem is that the injector control module needs 48v to run the injectors properly. Letting the batteries get low often will degrade the pump driver components, irreparably damaging them. You can put in fresh batteries, and the problem will persist because the driver module is now degraded. The symtoms are slow/lazy injection events that will result in hard starting and/or poor fuel economy. Again - people often blame the lube for these issues because it's an HEUI system, and it's actually not the lube that is the root cause. No synthetic oil, nor oil additive, is going to resolve this. Only replacing the driver module will fix this, and then keeping batteries in good condition will avoid it.
The 6.0L can be a very good engine, but it needs a bit of help with some aftermarket goodies. Once those are on, it's an ultra-reliable runner.