Hm, this is very interesting. I never dealt with it and always use carpet between speakers and listening position. What you say and what the db-system.fr do:
… suggest that randomizing the floor reflection do a lot of difference – pretty much what we have in concert hall. It is very plausible but I have no data or experience. I do not see why it would not work.
How to make it “sexy” in not dedicated listening environment – this of cause is the problem.
You might bread porcupines and at the time you listen you can feed them between you and the loudspeakers. The way how db-system did is very slick but I would not like to imitate it. The bigger question however is: how much the difference is and if worth to do it. I think the only way to answer is to experiment with it.
"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche