One important thing it's important to mention is that the Anker Nebula Mars 3 Air has no support for sound out via Bluetooth. This means you can not connect to external active speakers / soundbar or headphones. This made the unit a "no buy" for me as I often watch movies and TV-series wearing my Bose headset to not disturb my partner sleeping in the next room... This will for many be a normal situation since the projector really needs a dark room to perform and you end up using it after sundown.
If you connect e.g. a Google TV through HDMI to push sound out from this you end up with a "picture / sound out of sync situation" and no settings to adjust this...
Other projectors from Anker does support Bluetooth out so this seems to be something done to cut cost.