In my line of work (check my profile), I deal with characteristics that can be measured and quantified. A lot of the claims made by "high-end" manufacturers amount ot nothing more than the Emperor's new clothes. No-one is willing to admit that they can't hear the difference, but electronic equipment has no sense of embarassment, so it is unafraid to tell the truth.

Let's start with the conceit that some systems handle high frequencies better than others. Even when such claims can be verified by careful measurement, it is not possible for anyone to hear the difference between a 10 kHz sine wave (pure tone) and a 10 kHz square wave!