"Anyone who's genuinely interested in experiencing great sound from loudspeakers must be willing to do the work required in the room."
Good point. If the goal is indeed "perfect sound", consider how much effort goes into the acoustics of a good recital hall, wherein the unamplified voices and instruments naturally start out projecting "perfect sound".
What might make the most sense is engaging the services of a professional acoustician. Let me suggest Jeff Hedback, a many-times award-winning acoustician who is still affordable. http://www.hdacoustics.net/
I have stopped trying to armchair quarterback the acoustic treatment of people's rooms after witnessing how much better job a professional acoustician can do. Simply adding absorption to a room is like randomly adding resistance to a crossover. Just as a crossover calls for the right amounts of inductance or capacitance or resistance in the right places, so too in our rooms call for the right amounts of diffusion or reflection or absorption in the right places.
Duke