I, too, have seen a few people claim that Axiom's, as well as Paradigm, B&W and Mon A's are "bright", some even want you to think they might even sound harsh.
This is why I go to measurements. A lot of work has been done to correlate different measurements to the sounds that speakers can produce.
Starting from the fact that in blind testing we like a
slightly rolled off high end, take a look at any of the speakers you mentioned and you will see that they are flat within +-2 or 3 db across the audible spectrum: no roll off. That is why you see some reviewers that really like the M80s mention that they can sound
slightly bright. Its a subtle thing if noticed.
Harsh in the high end is usually a sign of driver breakup. Again, if you look at the frequency response, there is no hint of such an event in the measurements. The response remains flat and constant. Now, all metal dome tweeters break up at some point in the 20-30KHz region, but it is beyond the range of reproduced music and that of 99.9999999% of the population's hearing. Even B&Ws diamond tweeters breakup... at 45Khz. Now, if a person were to have unusual hearing, say up into the high 20s, then they might find the M80, or any other metal dome tweeter, harsh. IF.
Recessed = a depressed midrange Alan, in his comparison of an Energy speaker and the M80 pointed out that 2db difference is noticable, but quite subtle.
Warm = an elevated midrange.
Sibilance can be traced to issues in a certain frequency range (can't remember what it is)
The list goes on (my memory dosn't).
The point is, if you can hear it, it shows up somehow in measurements.
I agree with you on disregarding over the top comments. Generally, things that are measureble and show up in subtle ways.
