My wife was due for an upgrade and chose to go with the Nexus 5X. However within a week she was thoroughly dissatisfied and returned it. She paid the extra money to get the Priv and has been quite happy with it. Case closed.
Out of these 3 Device, i would prefer to go for Nexus 6P as it has better specifications and features compared to other two phones (Nexus 5X and Blackberry Priv). The Nexus 6P is decently priced and comes with all the features, which a general buyer looks for.
BlackBerry PRIV. Camera, physical keyboard and BlackBerry Hub is just insane. I have been using one for 4 months now and I can't put it down. And what other device on the market can take a SD card of up to 2TB.
I love my PRIV....