>My experience with the 109 differs from most. And it sounds different to me than it does to someone else.

Let me first start of saying that what you're hearing is not wrong, I 100% believe you. This is important because the reason you hear what you hear could have in my opinion based on what I know about this topics and what I read could have 2 reasons. The first is your hrtf doesn't match with the mean as pointed out in the paper we're talking about; you literally hear different.

The other reason is probably that you are used to other headphones which have a different response and because the meze probably has more highs than the other headphone you perceive it as too much highs. This means that the error is not that you hear different meaning (e.g. you have a different hrtf which was the point I was making) but that you are used to other headphones or just have a different preference. Comparing the Meze to the headphones in your flair seem to confirm that it indeed has more treble meaning the target represents your hrtf probably pretty well.

Really my point is that we are (most of the time, 80%+ of the people) not hearing differently but that we have different preferences (or known/used to targets), this is also supported in the harman target research paper which pointed out that some people like more bass and some less highs. This means in short (in my scientific based opinion at least) that if we both listen to a pair of dt990's after having listened to hd650's for a good while (so it is our definition of neutral and our only audible memory of a reference) that we both would think the dt990 is a bright sounding headphone and not still have different ratings because our ears are literally different.