I was expecting your prompt reply, even the "We, audiophiles" - surely with the exception of you, a few selected members and me .
99% of the people who infer that "while very good but can't be better than" do not have direct experience with your FM Acoustics example, but have direct large experience with as many equipment as you or me and have watched that as as general rule, when properly matched and optimally used, a more expensive item can return a better sound quality.
You second subject has nothing to deal with this aspect - if people are prepared to spend more money, designers are allowed to designed better products at an higher price. Perhaps some of them will not make a proper use of their extra budget, members of forums like WBF should warn consumers in such cases if they have sufficient evidence of it. The law of diminishing returns makes this ultra price zone a dangerous zone - any one knowing about error propagation and logarithms will understand it - a lot of experience and self control is needed here. Nothing new here ...
And yes, we all now know about the MG3.7 and ask ourselves why you do not consider a pair of MG3.7 or MG201.1 for you. Will you elucidate us of this mystery?
Sigh I give up! after this display of circular reasoning ..
but before I go I will politely answer your last question:
I have owned Maggies from the SMG to the 20.1. The new Maggies (.7x series) remain in my view contenders but I believe that cones have arrived. I am also more and more attracted to High Sensitivity speakers: JBL 4367 and Gedlee New Summa are speakers I will audition and so is the M2 system. The Q3 was very seductive to me and is still in the running. Will investigate YG and Vivid Giya Series too... Will take the time for the Quintessence Acoustic which by many reports are excellent ... so likely cons or horns for me and multi subs for the lows ...