Re: Lumia 520, 720, 920, 1020, 1320 Owners
My two brothers and I have been Lumia 920 owners for a couple years. My dad and step-mom both use a 1020. My older brother only recently asked me about the possibility of getting Windows 10 on his phone because his fianc? got him a Garmin Vivofit for Christmas, and the Garmin Connect app only runs on Windows 10, not WP8.1.
He started with build 10586.122 and upgraded to 10586.164 a few days later, but unfortunately, his Lumia 920 had terrible battery performance with Windows 10 Insider preview. I've been using a 640 XL on Windows 10 for 4 months, but I switched back to my Lumia 920 to see if I could duplicate the issues he was having, but mine ran just fine. After about a week of frustration, I got him a 640 and set it up on the Insider preview, and he is much happier with the performance of just the battery alone.
After resetting back to the official WP8.1 releases, I just sold both of these 920's on eBay this past weekend. My parents have no idea that they are missing out on a potential upgrade for their 1020's, and my younger brother won't care about making any changes to his phone until this one stops working and he's forced to get a new one. Out of four Lumia x20 devices in my family that were being used as daily drivers up until this week, I can honestly say that this decision by Microsoft has not left anyone in my family upset.
Three just simply don't know or care about Windows 10, and the other got a better phone experience and sold a 3 year old phone for more than he paid for its replacement.