7. People are designing apps for windows 10 and MS BAND 2, however many of us are reluctant to move to windows 10 insider due to the amount of bugs currently present. I do not know how many are still using 8.1 on their phones, but probably a lot simply because its stable...
There's a new insiders ring which i believe is for release candidates only, its even slower than the slow ring. It should be fairly stable, i believe in that stage they are no longer adding any features and are only doing critical bug fixes. Might that b an option for you? or maybe move to the 950 or 650, my 950xl has been great.