I put 325,000 miles on my old '01 HO/6 speed that now belongs to my daughter and son-in-law. It has 350,000 on it now and still runs fine, uses only a quart of oil in 10,000 miles, and produces excellent power. I drive it occasionally.
It had one VP-44 replacement early in it's lifetime by mistake due to a mistaken diagnosis. Also has had two lift pumps, two water pumps, and one head gasket. It has had Bosch 275hp motorhome injectors since 16,000 miles and I always ran it at 1300* - 1325* on the pyro when pulling long grades loaded, and often in 6th gear at 1600 rpm.
I consider those 24 valve electronic engines bullet proof.