Pure bollocks I'm afraid. Amplitude frequency response is only a small, and relatively unimportant, part of the equation. Of equal or greater importance are such factors as rise time, settling time and phase versus frequency response amongst others. For CD players in particular, the nature of the high frequency filtering is also crucially important as it affects how natural the player will sound (or how 'digital'). And yet we only ever see published figures for frequency response as if this were all that mattered.