That looks a bit more complicated and expensive to rebuild/fix than I would like to see in a truck.
We will see, time will tell. I'd love to see a contractor test that thing for 10 years. 10k-15k mile Jiffy lube oil changes, spark plugs when they fail, coolant, never, air filter? Maybe at 100k.
GM sells a ton of 6L's, and the old 4.3's for a reason, they don't mind abuse.
Remember this is a truck motor not an Audi A8 motor.