I use the Art Basik System. I have not pulled it from the room since the initial set up and things have changed since then, so I can't directly speak to how much it effects things now. With my SE34 amp the Basik system along with a Kemp SR unit, and some fiberglass stuffed under a low shelf was quite good. After tuning the Basik in, there was no question as to its efficacy...clarification, ambience and sound stage all benefiting. Likewise with the SR unit.

But with the Torii, this room became much more demanding, especially in the low end, after which I have done more traditional stuff with hard fiberglass board and a diaphragm.  

But even now, though I leave the Basik wall units where they are, when I occasionally play with the Basik Bass unit, shifting a couple inches to several feet, centered or off center, angled or straight on, I can subtly shift the sense of the room ambience from recordings into relatively seamless integration with my room. In other words, there is no separation from the players in the room, the ambient decay continuing all around me. It must be cleaning up specific areas of bass/low mid stuff in different locations, and there is definitely magic in the right place.

This could be specific to this weird room though! And I am not surrounded by ERRs with three amps driving them!