I used Windows Phone 8/8.1 & Windows 10 Mobile on a Lumia Icon, then got a Lumia 950 XL after 2 years. I hit my last straw with Windows Phone last month, and went back to Android. My battery was draining terribly, even on standby, my camera lagged or froze in crucial moments when I needed it most on my 950 XL, and a lot of the apps I needed were getting canned by their respective developers. I still use Groove Music, Word, Outlook, OneDrive, and other Microsoft apps on Android now. I hope Microsoft returns with a good Mobile OS in the future, but I feel as if Windows 10 Mobile, right now, is going nowhere. I couldn't stick around, and it was painful to switch. I still have my 950 XL as a backup and love using it from time to time still. If the Surface Phone rumors ever come true, I'll be back for sure.