I guess in some respects, I could answer this myself with a bit of testing, but I'm curious about others experience too, especially WRT noise cancellation. I have a full face helmet and I always assumed that the cleanest mic installation for the 20S would be to put the stick on, wired mic just off centre in front of my mouth. However, in this review of the 10C at the 5:26 mark they comment that the boom mic is better quality and better for noise canceling. "Fair enough", I thought, "I guess they must use the back of the mic for some sort of cardioid arrangement." However, having received my 20S, it doesn't appear that there is any opening on the boom mic other than on the mouth side of the capsule. So it too must be relatively omnidirectional and rely on proximity and DSP for noise reduction. Has anybody done any good real world comparisons? I'm not vlogging, so I don't need to capture the sound of my bike. Just looking for good, clear communications.