Glad to see...
...my mum's 630 is not on the list.
8.1 is a terrific phone OS, and very OAP-friendly for a smart phone.
10 may get there eventually, unless it's axed before then, but is still too rough around the edges, IMHO, and has lost a few of the little UI quirks (when compared to Android & iOS) that actually made it so bloody good in daily use.