No, I haven't heard them. But I do have a PolyCrystal two-shelf (UDF) stand, and I can tell you that this is very good at its job. I recently added a pneumatic shelf for my SACD player - a Bright Star Audio Air Mass 3 Reference. This is a very high quality stand, made of exotic substances with two vertically-oriented bladders sourced from the aerospace industry. This made a small improvement which made me think that the PolyCrystal stand was doing a good job. I was always pretty interested in the Diablo, because I figured the cabinet would be awesome. But we have had manufacturers try the exotic cabinet approach before, and by itself, has not led to a truly superb speaker. What's your angle here?