I had a Lumia 520 running WP8 for several years. If there's one word for this OS, it's "disciplined". It was easy on battery, it was totally stable (in my exp

I had a Lumia 520 running WP8 for several years. If there's one word for this OS, it's "disciplined". It was easy on battery, it was totally stable (in my experience anyway) and it was absolutely miserly with mobile data. For example the email client still used ActiveSync, a protocol which was designed when every byte still counted, and there was virtually no unexplained "operating system" mobile data usage. The discipline also extended to heavy sandboxing of the apps so a lot of functionality was simply unimplemetable, such as reminders for missed notifications. But the phone worked, the UI was intiutive and responsive, and the only reason to move on, other than general phone obsolescence like the 5MP camera, was the lack of mainstream apps. We had a brief experience with WP10 on another phone, and it seemed spiffier but less stable. WP8 was the high point.