I am a Europe based mixer and own 4 A20´s.
It is worth to mention, that in the end of the line the receiver gives out 44.1 khz.
This huge dynamic range, that is obviously responsible for the transmitters short battery life, puffs away afterwards.
And the battery doubler makes them in my eyes bigger than SMQV´s. (This update costs for older transmitters 250€!!! No, they did not say: sorry it´s for free, we did never test the runtime in normal workflow. )
Maybe they should step back to 24bit in order to extend the battery life (hopefully only a software update?)
I intend to add A 10´s transmitters to my system. They last more than half a day with NIMH´s.
My receivers work perfect (A 10´s). Designed in England.