Highlighting passages doesn't seem to work for me here, Marco, but your mention of some people 'buying by measurement' reminds me that this was indeed the basis for purchase of (or drooling over) kit in the 60s and 70s; certainly the early s/s amplification but much else beside. The T.H.D., wow & flutter and whatever, ad nauseam, was the thing stuff was sold on.
Naïve, maybe, but fun regardless in those halcyon analogue days of R2R, cassette, quadraphonics...(mood has just changed; delete last one). Nostalgia's not what it used to be.