The only measurement that is truely relevant to this discussion (and that is almost never performed because of its cost) is a statistical analysis of a psycho-acoustic experiment properly designed and executed. All our electrical test equipment only gives us a hint of what our ears and minds are capable of perceiving. -- And yes I have an MA in psycophysics specializing in acoustics. That leads me to believe that anecdotal evidence, based on perception, even without an experiment is worth paying attention to. In fact, I would guess that many designers of high end equipment base what is unique about their designs, in the final analysis, on listening rather than electronic measurement (what good is it if you can measure it but cannot hear it).
I don't mean to suggest that we haven't learned a lot from these imperfect measuring tools or the mathematics that go with them. I'm a strong believer in correcting room anomolies as much as possible and even use digital eq to good effect (so much better than the old filter approach). But ultimately we're talking about music/sound which is perceived by a listener, and the listener is what counts.
What I find strange about many of these kinds of discussions, is that participants often pit electronic measurements against human anecdotal evidence. If your skeptical about anecdotal evidence, the answer isn't to turn to a useful but imperfect machine but rather to properly perform psycho-acoustic experimentation.