Hard to say. Most of the numbers are greek to me, but I get one done every once in a while just to check on how things look (no bypass set up for me). How long have you been running the Schaeffers? I've heard that wear metals increase the first couple of changes while it cleans things out on a regular oil change. I'm not sure how that translates to extended drain intervals and a bypass set up.

Who did all the testing for both methods? Did you ever consider getting another lab to do the chemical analysis?