The Autumn/Fall 2016 top smartphone choices for business/enterprise as well as the general public in my opinion are:
|Google Pixel phone||prosumer, management, executive||latest top hardware and OS, instant OS updates but $800+ for useful options|
|Blackberry DTEK60||everyone||modern hardware, recent hardened OS, $500|
|Blackberry DTEK50||budget-conscious||moderate hardware, recent hardened OS, $300|
|Blackberry Priv||physical keyboard||year-old top hardware, recent hardened OS, $500|
If one is facing sub-$300 budgets as most of the world is, consider a phone listed on Cyanogenmod. It will take a bit of tech savvy, but you can buy a cheap device used and reflash to Cyanogenmod with the latest updates. You will need to ensure the device you buy is supported by your carrier. Verizon is a carrier to avoid in this regard; they are typically hard to flash for as a unique CDMA carrier. T-mobile is one of the more friendly carriers.
The Google Pixel phone specs outweigh Blackberry in essentially every way, except for the classic lack of micro SD slot in the Pixel phone. The granular app permissions of Android >= 6.0 make the DTEK app mostly a permission use logger.
Having Android security updates before anyone else, sometimes even including Nexus/Pixel is a very important reason to use Blackberry (unlocked, not through carrier) over typical carrier handsets that might never get updates in an age of zero-day attacks. Blackberry’s deep EMM experience leads to custom security enhancements to the Android system not available on other handsets.
Blackberry repositioned themselves in Sept 2016 in a much smarter way than the introduction of the high-end priced Priv in Nov 2015. As a low- to mid-priced hardware vendor, Blackberry presents an excellent alternative to Google Pixel handsets, having hardened security at widely-affordable, competitive prices.
Samsung Knox: reputed to have underwhelming performance, not impressed by what I read w.r.t. security.
SilentCircle: Blackphone 2 has mid-2015, dated hardware.
HP Elite x3: very high price, Continuum for practical purposes can be done with “freerdp” software for legacy Windows apps from a non-Microsoft phone.