I wrote this answer on Quora and thought it may be useful to share with you faithful blog readers.
Answer by Bayan Qandil:
I haven’t used the final BB10 for me to make a proper statement here. I did use very early versions of it and I’m very familiar with the typical BlackBerry Value Prop. So here goes…
Number 1 – Keyboard
Everybody mentions this and I will too. BlackBerry’s hardware keyboards are the best in the business… second to none. And with BB10, they build an impressive looking (again, haven’t tried it) looking and innovative virtual keyboard.
Number 2 – Reliable Real-time Global Communications
I never noticed this until I switched off of BlackBerry. And honestly, most people don’t care. But BlackBerry is one of the few companies that can deliver a message reliably in realtime anywhere in the world using their impressive network. That is why BlackBerry is still top choice for many humanitarian (and likely black market) purposes.
Number 3 – One Handed Use
BlackBerry is designed to be used with one hand. If you see any of the UX design standards for BB10, you’ll see that theme throughout. The fact is, you can do a lot more with one hand on a BlackBerry than with any other device.
Number 4 – Cross Application / Service Integration and Usability
BlackBerry was always designed (pre-BB10) with seamless integration of data sharing across services or apps. For example, I could take an email, highlight a sentance, share it to Facebook, Twitter, BBM and SMS it with only 2-3 clicks. With one hand I might add. Try doing that on most devices these days. Note that I don’t know if this is still the case with BB10.
Note that none of the things that I mentioned can be accomplished by an App because they are design qualities and themes, not task based benefits. And BlackBerry will likely never be able to win in that category mostly due to the cheer volume of Apps on Google Play and Apple’s AppStore.
Hope you found this useful.