I think most of us are comfortable with side-by-side comparisons. Take two amplifiers and within the space of a few minutes decide which sounds more musical.
It gets exponentially more difficult when we make comparisons from memory because we each remember differently. For instance, my memories of specifics are weak while those of emotions are strong.
I easily remember how an amplifier made me feel or how engaged with the music I was. I can’t specifically name the details of what prompted those emotions.
This becomes particularly more difficult as it concerns loudspeakers. There’s no easy way to side-by-side compare them. Even ignoring the obvious difficulties of moving in and out large heavy pairs of boxes let us not forget that where in the room one set of speakers shine another might fail.
Speaker setup is so particular to the room that it’s nigh impossible to do side-by-side comparisons of speakers.
Yet there are no more important pieces within our systems than they.
And so we must rely upon our memories when it comes time to decide what speakers are best.
I hope your memory is better than mine.