The all-electronic S1? That headset intrigues me greatly.
I recently bought the U-Fly Mike to go with my Bose QC-15s, just to give it a try. It works nicely, but I'd have to put them side-by-side up against my partner's A-20s sometime. My buddy's Maule was a little bit too much for the QC-15s at a couple of points, and they just gave up and the ANR stopped working for brief periods. I'm sure the A-20s and comparable don't have that problem given what they were designed for.