Although I agree that the "man in the street" is capable of giving a consistent opinion without training (meaning he can repeatedly identify which one is which and giving a subjective evaluation), I don't think he is capable of a detailed evaluation. I mean most of the times, he will prefer the system that has more bass and treble, less nasal midrange, favor 2nd-order harmonic distortion, and so on, but will not be capable of isolating these characters.
Trained "listeners" know how to isolate particular areas of the system's reproduction, and evaluate them independantly, like a wine-taster can evaluate separately the sugar, alcohol and tanine contents, the different aromas and constituents of sapidity.
An untrained listener will tell you "I like this system better than that one", a trained one will tell you " I lke the bass, but not so much the upper midrange, and I think there's some distortion here"; to me the latter is more useful, because it allows me to concentrate on a specific area, instead of sitting here pulling my hair.
When the differences between two systems are multi-dimensional (different frequency response, different distorsion behaviour, different recovery time, different crest factor), an untrained listener may mark as equally good (equally bad?) two flawed systems, without being capable of pinpointing the high and low points.
The simple "I like it better" comment may be conflicting with the design target, particularly if you're targetting at "truest".
I believe you are very familiar with the notion of acquired taste. I think you can't prevent that notion to interfere with all subjective tests. Part of the training for listeners is to be capable of isolating from this notion (not ignoring it, which is impossible IMO) by decomposing a global performance in separate factors. Some are naturally capable of doing it to a point instinctively, but it's a gift that needs to be nurtured.
As to "HiFi Reviewers", I recently went to the doctor's and read a review of digital music servers (no one would actually catch me buying an audiophool magazine). I had the pleasure to know that some were notable for their "suavity" :