My Blackberry Q10 served me well for years but the battery is starting to go and the OS + apps are no longer supported. I can actually say I've skipped Android/iOS entirely.
I just got mine and it is significantly buggier, crashier, and slower than expected. The USB C port is also of low quality. It is overall worse quality than expected.
It's coming along fine though and in a few years that might be true! For now, a great device for tinkering and contributing back.
Source: I've used the Outlook app before my phone was enrolled with my company so I noticed the differences :).
Still Android, but you keep the HW Kepboard and the batterylife and build on it is insane. Not nearly as clean as stock or the Key2, but much more freedom respecting.