Is it really possible to compare A/B speakers??

This post is directed to the more technical members of A'gon.

I've been reading numerous posts and audio reviews which compared various brands and models of speakers against each other. For example, in one thread a member said he was sure speaker A sounded all-around better then speaker B because when the two speakers were compared at a dealer's shop, they were in the same sound room, driven by the same equipment, same source material, and so forth. For discusion purposes, let's just accept that all relevant conditions were the same.

Here's my question. Even if all relevant variable factors were controlled and the same, can one still fairly say they "A/B'ed" two speakers??

And here's the basis for my question. As I have been reading and trying to understand the science and technology behind what drives input signal to speaker output, I have come to appreciate that there are many other variables that can affect what comes out as sound.

For example, every speaker on the market has it's own electronic fingerprint so to speak that can affect how it interacts with the amp being used, e.g., efficiency, impedance, phase angle, and so forth -- all of which changes over the frequency range. I'm not even touching on home room acoustics.

Another case in point, one member (M-1) commented that a certain speaker (A) he listened to at a dealer sounded hot and caused hearing fatigue as compared to another speaker (B). He fairly concluded that speaker B was the better sounding speaker.

Interestingly, another member (M-2) questioned how M-1 could come to such a conclusion. His experience was totally opposite.

I don't recall that either member mentioned the type of equipment that was being used. However, M-1 was certain that the dealer listening conditions were identical.

Many of the more technical A'gon members have posted numerous threads about the synergy or lack thereof between tube amps and solid state amps with varioius types of speakers that present certain loads to the amp.

If such is the case, then I'm back to my origianl Q. Is it really possible to compare (A/B) speakers even if conditions and variables are identical??

If the answer (or consensus) is "NO," then how can one in the market for new speakers make an intelligent and informed decision?