I'm content with my choice to stick with a Series 3.. I will believe it when I see it. Generally you're correct, those who have a negative experience are the ones speaking up. But until I see a display that is consistent posted, what is more anecdotal?
Your post does bring up one good point, if anything, if this really is a ‘problem’, which it may or may not be, I would think that if one member would contact Apple who is experiencing this problem, request to speak to someone in quality control, and send pictures to Apple of the display concerns, Apple at minimum would want to at least capture the defective Series 4 for investigative purposes, which they would issue a replacement watch if Apple determines that in is fact it is a defect.
I don’t disagree that it’s distracting once you notice this un-uniform display, but how many ‘Average non-tech users’ would go to the point of where they actually feel it’s necessary to conduct these tests to observe the display disparity on a daily basis that never perceives to be a problem? Those are two different things.