I had heard Flyer's system before, which is full of SMT treatment, and Flyer had mentioned that the regular audiophile does not need so many wings - 1 behind each speaker, 1 behind but in the centre, at first reflection points, and on the ceiling are sufficient. This is exactly what I got to demo at Jazzhead's place in Mumbai last week.
His Marten Coltrane 3, powered by Vitus class A amp and Wavac PRT 1, are in a room that though long (25ft) is narrow (11 feet). He has made the best of his room though by pulling the speakers out a fair distance from the wall, and placing the SMT wings behind them, 1 behind each speaker and 1 behind but in the center. We are able to AB with and without. He also has first reflection points fixed to the walls that cannot be ABed, but then he has 1 wing on the floor in front of each speaker, raised up at a slight incline towards the speaker, and this could be easily ABed.
During each AB, there was a significant drop in soundstage, 3d, flow, and focus. With them in, the room seemed bigger and the bass and stage behind the speakers had a nice depth.
At flyer's place I had ABed the wings behind the listener, and at Elberoth's I had ABed a pair at first reflection points. Given the aesthetics of the wings, I am quite convinced by them as a product and will look for wings at key positions once my new room and speakers are ready.