I own one, it's been great, 170,000 miles. Cleaned the turbo vanes and soldered the idm, replaced the alternator. That's it, been a fine truck.
I've worked on many, they can be a problem. Worse yet it's the half arsed repairs that cause big failures. Well ignoring small issues until they get large will do the same.
Main thing is if the egr cooler fails, change it over to a bullet proof one and change the oil cooler at the same time.
If it starts and or misfires cold check the idm voltage, replace or repair that. Keep it's fuel above 1/4 and fuel filter clean.
After that drive it.
The head gaskets might start leaking around 175,000 miles and the cam will go out at about 8000 hours. But that is a LONG time for a non comerical truck.