Isn't that all stuff every headphone manufacturer's marketing department should be doing before the launch of a flagship product?
It sounds like good business to me. Manufacturers whose marketing departments don't do this kind of PR rollout are probably doing their product a disservice, don't you think?
I don't really see any ethical issues unless positive reviews were paid for.
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In any event, the high-end of the headphone world seems to be reasonably good at separating the wheat from the chaff once the initial buzz settles. The cream has generally risen to the top (Sennheiser, Schiit, Stax) while the mediocrity has Been sinking (Audeze, Ultrasone, Basically Every Custom Cable Maker).
As usual, early adopters put themselves at risk of falling for the buzz, but this is and will always be the case.