If I were considering such a purchase, I'd simply ask the sales person to hook up an audio analyzer, and show me the difference in output empirically. It's hard to admit, I know, but a $200 student/enthusiast grade oscilloscope is more sensitive to signal nuances than the most discerning ears, by several orders of magnitude. Odd how ads for $800 cables NEVER include any data. No numbers, no graphs, no oscilloscope screens, nothing. There's always testimony about how drastic the sound improved. If I built a component that was that noticeable, I'd commission a 3rd party lab to do double-blind testing to verify, and put that data in my advertising.
