Keith, as you recognize at least to some extent, listening to different speakers at different locations at different times is nearly useless unless one of them is grossly inferior. Same place, same time, same music, volume set to same overall level(not just the same number), all of this is necessary, and blind listening would be even better.
Regardless of the price difference that you mention, it's difficult to believe that the other speaker actually has better treble detail than the M22s. An excessively elevated treble response(if this is the case)shouldn't be confused with better detail, but instead properly viewed as less accuracy.
