I'm not going to even comment on Mr. Ayers non-sense ( This was a spark plug thread turned into a GM TSB thread.. ) anymore but from my own observations..
The factory Platinum plugs.. Their good for maybe 50,000. I've changed some on those from the Buffalo area's trucks. None had power adders or even cold air intakes. All were pretty bad.
I use copper plugs myself, a stage or 2 colder ( Nitrous/Bottle fed ) . No ' factory ' or ' non specialty ' Platinum plug is really going to last with forced induction that I have seen *personally*.