I am in a heated discussion with Ram hater. He says my actual payload is lower than what the door sticker says. I think that it is mainly because mine is higher than his Chevy. My sticker says not...
We used to have a guy working with us that was like the guy you described. His Cummins was the greatest, blah, blah. His Cummins was going to last 400,000~500,000 miles, blah, blah.
When he started his rants we would ignore him. He finally took another job elsewhere. Happiest day we had in many moons.