After living with
BT-300's for about 4 months, I have a few observations to share:
I got them last winter when EVERYTHING here was covered with snow, and it was impossible for me to see anything useful on the screen of my 8" Samsung Galaxy Tab 2 with the sun reflecting off the snow into my eyes. I even made a hood out of coroplast and black felt that made me resemble a 19th century photographer. It enabled me to see the screen, but blocked out everything else, so I was blinded by the glare and had to attempt to re-acquire LOS of my Mavic every time I came out from inside it. The Moverios solved that problem, but it was frustrating to not have access to maps.
I tried to use Ender's procedure for loading the maps via Google Account Manager and Google Play Services, but it was such a PIA to enter my Google credentials with the
Moverio touchpad that I could never tell if I got it right, so I continued to fly without maps.
At some point, I upgraded to the latest version of DJI Go 4 and the latest firmware on the
Moverio and Mavic, and, miraculously, maps are now working. Maybe all my flailing around with Google accounts did something and the maps loaded. I still don't understand what happened, but I'm not complaining unless the maps disappear.
I've tried the RO sunshades and the dark and medium sunshades that came with the Moverios and settled on the medium density shades. While the screen display shows up great with the darker shades, they're too dark for me to track my aircraft against the deep blue high altitude (8000') sky where I live.
It's doubtful that I'll return to using my tablet for DJI Go 4, but I can at least use it for e-books, web surfing, et\c.