I'm relatively confident that most of speakers I've heard have a character of one sort or another and I could identify which is which (blind) to a high success rate. I think it is all just a case of finding which is most pleasant/least unpleasant to your ears. All of these characters I could probably give names too, depending what I hear i.e boomy, tizzy, plasticky, dull and so on.
For naysayers, I imagine there is some continuity among terms people use and the faults of particular speakers. I mean, who argues over the term boomy. Why is boomy acceptable as a term, but plasticky isn't. If plasticky was found the describe something repeatable about sound quality, could it be accepted into the audio lexicon then?
No idea about whether Neumann's sound plasticky or not though, sorry OP.