I had a Lumia 830 until the bitter end (of security updates—2019 I think) and I agree it was really nice to have a third competitor. But I also got it back out of the drawer the other day and was reminded of how buggy it was, especially after the upgrade to Windows 10 Mobile (on my phone I had a nasty memory leak that made the browser unusable after going a few days without rebooting, and an issue where photos you just took would get deleted if you viewed them immediately after pressing the shutter without waiting a few seconds). I also think you can't print with it, at least not without a third-party app, so AirPrint on the iPhone was very nice for me.

Definitely ahead of its time in certain UI concepts, definitely didn't get the attention it deserved to iron out some big defects!