Most, if not all of them will say that, it is to be expected.
It goes like this:
- manufacturers list a few features of their products that could explain why theirs will sound better than others, and why their more expensive models will sound much better.
- people who are keen on sound quality read them.
- sales people went to manufacturers events to get demos and educated.
- sales people tell their potential customers the same stories they heard, elaborate, exaggerate..
- potential buys got oriented, tuned in, and by then biased enough to enable them to hear the claimed difference, benefits, i.e. better sound quality.
It doesn't how many times objectivists that include technically inclined reviewers such as Gene, Amir, or experts such as Dr. Olive, Toole, Geddes and other Ph.Ds who have done lots of studies explained the need to do control tests for unbiased results, people will believe things as long as they are given enough reasons. Such reasons typically include certain unique features such as RC software that have great interface, calibrated good looking mics, design topology and/or hardware such as class A, feed forward, current dumping, high end opamps, HDAMs, toroidal PS transformers, expensive storage caps, MOSFETs, etc.. In the end the process are dominated by expectation bias, Placebo effects, and groupthink (evidence in owners threads on popular forums such as AVF, AVSF, Audioholics and even our beloved ASR!!
That's just my own opinion, but I know it does reflect reality.