Good for him.

Car A has been running great on oil X, but oil X has been shown to be a somewhat inferior oil.
Car B has been running great on oil Y, which has been shown via repeated oil analysis tests to have some of the best wear numbers in the industry.

Which would you choose? If you picked oil X, then have fun with RP. Will it kill your car? Maybe - maybe not. Do you use FRAM oil filters? I sure don't. Will they kill your car? Maybe - maybe not.