Vulcan607,
I really enjoy the A20 features. It is extremely quiet and the Bluetooth works great for cell use whether plugged into A/C inst. panel or not. A real benefit on a busy flightline O/S the cockpit.
You can listen to music from cell phone using a supplied 3mm cable. Both the cell audio(phone calls and music) mute upon receiving ATC xmission. You set the priority on the control module.
I made a 3G call from 3500ft today with no problem at all. Voice quality excellent on both ends.
I have used DCs and others for almost 30 years. The A20 is the best I've ever worn period! They are very comfortable and I actually have no soreness or pain as with others.