Im using one, it is basically silent unless you put your ears near the charger like 6 to 7 cm...then you can hear a very faint humming noise produced by the fan...you can feel the air flow of the fan too if you put your hand on the vented holes behind

I got the gear app on the phone update instead on my watch...it should enable better support for Gear Sport and IconX 2018 which is going to be released in 27 Oct 2017..