While it was a prototype at the time, I've mentioned before that hearing the 30.7s on a Magnepan dealer tour in 2018 presented some of the worst sound I've ever heard from a speaker in my life, with weird phase issues and other problems. (For example, the instruments had good presentation but somehow Sinatra's vocal was weird, appearing diffuse and not at all focused when on that track, it should be razor sharp and locked.)
I also mentioned they were actively messing with the crossovers during the demo using bare coils and standard alligator clip jumpers (!).
I finally found the photos I took of the event ("without pics it didn't happen), so: