From my own experience and from reading various forums, enabling encryption has a decent chance of putting your phone in a state where it will randomly and frequently reboot. At least, that's the theory; I'm in the process of disabling encryption now, so soon I should know whether that makes the reboots go away. Other than that, some of the setup is a bit weird, and other things just take some getting used to.
The app store (BlackBerry World) is a bit empty. I've found most of the apps that I need, but if you're looking for a specific app (especially anything from Google), prepare to be disappointed. I haven't started doing any development, but the docs generally look good, and I'm really excited to get my feet wet with Qt Quick on a phone. I think they made the right choice there, although I haven't actually gotten into it yet.
So, overall, I do think the Z10 has great potential. Something about the entire UI just feels respectful of the user; it stays out of the way and it almost always does exactly what I want it to do (unique in my personal experience with touch-based devices).
The Z10 has a 1280x768 resolution on a 4.2 inch screen. That is a 355ppi pixel density. That is better than the iphone 5(326ppi) and Galaxy S3(306ppi). Samsung's S4 although is a different story.
I write most of my apps in Python, and they work beautifully. I'm able to rapidly prototype and make changes as needed. Having done a lot of Android development, I can say the BlackBerry development tools and methods are actually easier and better to use. I think iOS dev is still more mature though.
Sales for my app have been decent. I need to push out an update soon, and do some more marketing to help it out though.
As a user, the device is great. I'm running the release OS on a Dev Alpha B, but I'll be getting a limited edition device once I ship this prototype back. It's smooth, fast, and works the way I expect it too. Again, having several Android devices, I can say that that OS never worked quite the way I did.
The other is to go deeper and integrate with cascades UI and process messages between the QML/Qt framework and a python event loop. [1] Project going this route can be found at http://hg.microcode.ca/blackberry-py/src/
Other "semi-supported" interpreters include Lua and Erlang. [2] I'm sure someone has a ruby vm by now.
[0]: http://peterhansen.ca/blog/bbx-python-direct-entry-point.htm...
[1]: http://peterhansen.ca/blog/blackberry-tart-preview.html
(Disclosure: I'm one of the lead contributors.)
Ah! If only you could code android apps in python. That is a plus for BB in my book.
a. The OS felt as responsive as Windows Phone and all the custom gesture recognition works as advertised(e.g. Peek).
b. The apps I used included Twitter, the Blackberry Hub (e-mail, contact etc.), the Camera app and Evernote. Of these, the Evernote app seemed to be a little rough (mainly UI glitches), but the rest worked well.
I haven't used the Developer Toolchain for QNX/BB10, but have friends who seem to think that it's not too bad. They are waiting for sales figures to decide whether or not they should think about releasing a BB10 app.
Off-topic: As someone who likes tinkering with things, hardware repair-ability is something I pay attention to. The Z10 is the most repairable phone out there according to iFixit (8/10): http://www.ifixit.com/Teardown/BlackBerry+Z10+Teardown/13445...
So it's still rough and there's not much good will on the dev side.
If you want the long one: I do maintenance for older (OS4~7) BB apps so I have an interest in where the platform goes. I'm following the evolution of the new OS and SDK since the playbook to the alpha device and up to the Z10, but even after the bbconf workshops on webworks or the sessions on cascade I don't see a future for native dev on this platform, and most of our clients just want their android app ported to BB10.
From the dev perspective, I don't see a good ROI in deeply learning the platform, so I'll be happy with watching over the shoulders of the guys dealing with it. Hearsay is OK for me when I see the support tickets flying around. Like there is no simple way to have the scroll position of a listview in cascades...that's just crazy when so many apps will be managing lists.
As a user, I'm not in the target audience since they never bothered to add japanese input support, but I tried most of devices by pure curiosity.
I genuinely wonder what particular feature is so well executed that you wanted to dismiss my opinion. I've seen some feature here and there that aren't bad, the focus on gestures is distinctive and there is a definitive push for a "modern" feel...but I'm not a big fan of the swipe up/down gestures, as actual content can be found near these areas, and it conflicts with other operations (like drawing on the screen). Even the task switching is tiresome at times, as app order is not fully predictable (or you have an excelent memory)
Is there any aspect that is not decent but really great?