The z30 is the best goddamn phone I've ever owned (and that's been: Motorola (last GSM brick model), Nokia, Motorola, Motorola (RAZR), HTC (Desire) and Samsung (Galaxy).
Basically I got sick of Android never feeling "finished", one annoying thing would get fixed but another introduced, or things that were useful got taken away. Constant bloody change for change's sake. (Don't get me started on grey text on a white background - WTF?)
Then there was feeling like I'd gone back to a Windows ME PC loaded with bloat/crapware and an apparent, "We'll do security last" attitude. I've never trusted Android enough to perform anything financial (like banking) with it. Particularly anything browser-based where the baked-in browsers only get updated with the firmware (i.e. never). Then there's the whole not being able to un-install the vendor or carrier's crapware to save space or bandwith use or to reduce attack surface. The utter lack of regular OS updates for ongoing, evolving security vulnerabilites, because you have to rely on the handset vendor and not Google.
I've used Apple kit and it's OK, (I'm not sure I like the new visual design ethos though) but the growing number of voices beginning to complain about the perceived drop in the quality of the software was off-putting, then there's the whole fashionista-cult-like nature and Jobs-worship amongst Appledom that's more than a little weird for a friggin' phone.
With the BlackBerry 10, I get around two bars signal in places where my HTC got none, the call quality is excellent. I could immediately un-install the bundled Facebook, Twitter and Box and installed (native) ownCloud and LinkedIn apps. I've easily found native apps or web-apps (excellent browser BTW), for everything I already use. Strong encryption, excellent security model and highly granular app-privilege controls, hell I can even un-install the clock app! Oh and the OS has a built-in traceroute and NSlookup app - that got me on geek-factor alone.
The desktop/tablet app "BlackBerry Blend" is like having my own personal cloud, without needing any third-party cloud provider - it just works and is really useful. Then new BBM app combines the best of (old) BBM, Skype, WhatsApp and Snapchat in one place.
My only worry is they might get bought by one of the big three and killed-off in favour of very inferior OS's or Chinese or Korean companies which means two things will probably happen, the security and privacy will go out the window and the elegant and business-like interface and design ethos will go all super-kawaii Hello-Kitty or Samsung/LG soulless conformity.
Yes, I'm evangelising, but what the hell, BlackBerry 10 is bloody awesome and the z30 phone hardware is a delight to use and the finish is excellent. More people need to sign their praises. That and we desperately need an alternative to the American big three (if you count MSFT).