Just for the record, the measurments included all measurements (bandwidth, harmonics, IM, step signal(ringing)) typically used at that time, and typically used in marketing stuff and to limited extend in reviews. FTT for instance was then limited to highly specialized R&D laboratories, and not generally used.
In my case it was performed with calibrated quipment.
Nevertheless i agree with you that it must be measurable. And there are reproducable measurements that show for instance that cables do show different characteristics, and yes there are audible differences, and yes different is not always better.
Nor are so called blind tests above any error or disruption therefore of absolutely not of undisputable quality, check the archives of HiFi News & Record Review for instance.
I also agree that marketing and sales in the Audio realm preferred mystique (or snake oil, or ..) over real reproducable arguments, it simply made more money.
I do not agree that the "differences without distinctions" is limited to hobbyists, after all it are mostly educated professionals that design and produce the stuff. Just see if you can retrieve some biography on Andy Rappaport.
That is what concerns me in the photography realm, this history pattern repeats itself.
Also pure simple logic says that the more sites in a sensor for a given scene to take a picture form, the more data about the scene is captured in the picture, the bigger a site, if all other parameters are equal, the better the SNR is. So the next thing is the ADC, there a lot can go wrong, etc.
If somewhere in the total chain a limitation in resolution is introduced, some part of the signal is lost and cannot be restored again in subsequent stages of the chain.
So i agree with you about your statement being puzzled by the DxO quality measures, and agree that numbers do matter, and yes they, unless complete and proven correlated with human perceived results, only tell a portion of the total picture. Until then, just do not let them become leading in assessing quality.
I like your indication "artistic quality".
For the past 30 years, I've been professionally involved in designing signal processing systems for audio, sonar, radar, and telecommunications systems. I've also read way too many statements about the mystical ineffability, the 'magic', the unknowable connection between design/implementation and perceived performance. If your two pre-amps measured "identically" (presumably in frequency response) and performed differently at a level reproducibly perceptible to humans in blind trials, then you didn't do enough measurements. Perhaps it was phase or amplitude non-linearity, or transient ringing effects, etc., but if its a gross enough effect for a human to distinguish, it has a measurable (in some parameter) effect on the signal waveform.
I'm not saying that different designs don't sound different, or that people shouldn't prefer one device's 'interpretation' over another. People can be pretty good at 'different', but we're really terrible at 'better'. Outside controlled blind trials, we're not even very good at reliably detecting differences among similarly performing gadgets. The shameful/successful marketing of $1000 per foot pure crystalline-aligned unobtanium-alloy speaker cables shows how effective the marketing guys are at creating distinctions without differences in the minds of vulnerable, enthusiastic (well-heeled) hobbyists.
Much of what is sold as high-end audio today is quantum snake oil. The tube amplifiers that are so popular today among the 'golden ears' MR refers to sound good in their judgment, but they're (by design) not high-fidelity, if hi-fi is taken to mean faithful reproduction of the audio signal. Tubes are well known for their compressive amplitude transfer characteristics, which in a nice Class A configuration (with little feedback to suppress the harmonic distortion) will produce the sweet 'syrupy' harmonics (distortion) that the golden ears have declared to be High Fidelity (its especially sweetening to acoustic instruments and human voices. I even like it.). Their preference for low-power final amplifiers (or overdriven pre-amp stages) is to insure that the tubes are frequently driven into their compressive performance regime. Its fine that they like it, and that they are willing to pay for it. Defending their 'refined' listening preferences by saying there's no correlation between measurements and quality though, is a rationalization of their preference for harmonically sweetened playback. High-fi it ain't. (I'm sure there's a Kodachrome/Velvia analogy in here somewhere - look at all the pretty colors)
So, while I'm puzzled, along with many others, with the DX0 'resolution independent' quality measures, I can't subscribe to the 'numbers don't matter' school. Badly formulated or mis-applied metrics are common. More common is mis-interpretation of technical measurements by non-specialists. Most common by far, sadly, is over-reliance on, and endless yammering over the the importance of this or that technical parameter in what is, outside of medical and forensic imaging, an artistic endeavor more than a technical one. The numbers, properly formulated and interpreted, can characterize the performance of the instrument, but can't predict the artistic quality of the product.