Ive had some very good soundstage affects but, never made my Maggie 1.7i s disappear however, another " cheating way" as mentioned, listening in the dark or in my case dimly lit room really changes the visual / accustic dimension. I also project a DJ light / party light againest the front wall. This seems to open the front wall and distract the eyes from the speakers.
May sound silly, but the soundstage is so much better than lights on or day time listening. .
I once heard old Polk Audio box speakers ( forgot model #) that used their unique interconnenct between speakers. The phantom sounds from way beyond the speakers was amazing.