I agree with all those arguments. I learned from experience a long time ago that is very easy to bias people if you tell them your impressions before they make their hearing. I have told people that have came to my home to hear stuff that I will not provide them my opinion because I want to hear from them and theirs and be able to compare with mines. I 100% support what you are saying.I haven't learned that from reading papers but from experience. I also think your opinion makes complete sense. You expressed it perfectly. Kudos for that.
First about biasing someone. You can say nothing, ask them to listen and tell you what you think. You know what is likely to happen? They'll hear very similar to you. How? Look up Clever Hans. We are influenced easily without anyone meaning to do so or even knowing they have. I realized over time when some of my friends had some new gear, I could tell what they were thinking about it by which recordings they decided to play. I didn't even intend to notice, but when I did I would know right away "what they were hearing", and realized I probably had done so for a long time.
However, as I said before, I mutated my position from being a 100% measurements and specs guy to a always hear what you buy before one. Because the "transparent" measurements from different products I have bought always, 100% of the time, I have been able to spot sound signatures, defects and virtudes. I have learned that all audio products have audible virtudes and defects no matter how perfectly their measurements or specs are.
I have also disagree with many products reviews as my sound impressions have been very different and my measurements where also different from the ones published. My best guess from this phenomena Is that many manufacturers send golden samples for review or some magazines gave positive reviews in exchange for paid ads (I know It is not the case of ASR)
Respectfully, you almost surely didn't hear actual sound differences from differences in sound. You haven't level matched, you knew what you were listening to etc. It is quite common for people to have the idea cheaper gear is less smooth or has bit less soundstage etc. etc. You get the same from reading reviews as well as the Clever Hans influence. The idea about manufacturers sending golden samples has little merit. I don't know what measurements you were taking that differed. A number of people here if you look around may not have an AP device like Amir, but other devices are not far from it and they get measurements that match quite closely with different samples of the same gear. You'll also find the basic measures by Stereophile are generally in close agreement with Amir's.
This sort of thing is well established. Many of us have been there. It seems too real and unbelievable that what you are hearing is not different. Yet a 1/4 of a db will sound perfectly level matched and will reliably cause you to hear better quality from the louder device. It does not sound louder, it sounds deeper, warmer, more detailed. You'll think it is the better sounding device.
Have you listened to the tracks I made available that were 8th generation copies? If every device has a sound magnifying it 8x should make it obvious. Try that and see what you think.