Depends on the one I suppose, but a knowledgeable one with years of experience that has for example taken 10 Ford 6.7Powerstrokes and ran oil X, and 10 running oil A and 10 running B, for several hundred thousand miles of tough abuse and noticing a significant reduction in engine/emission related issues and for another example of finding excavators with significantly less pin and bushing wear with brand x grease over brands A, B, I would personally take that over any keyboard warriors UOA, that’s running “one” of something with nothing to compare or test against. But as mentioned above, to each their own.
