You have been at this a while! I too have listened to Hill Plasmatronics and they were amazing. I've heard almost every Accustat, Maggies, KEF, Dahlquists, Time Windows, Advents, double stacked advents, and a LOT of conventional speakers. I ran a high end store in the late 70s, then was a hi fi rep out of Chicago in the 80s.
You say "The problem for Active speaker designers is that the room is an integral part of the system." This is the problem for EVERY speaker designer, active passive or any design between. This is the mystery sauce behind so many radically different opinions/posts about a given model or brand: "I tried that, it was awful", then "Hey-I own that, it's marvelous". It's all about the room, making a speaker wonderful and awful at the same time. This is the confusion of speaker demos- you aren't demoing speakers, you are demoing the room.
Brad