I bought this to replace a Nexus 5 that I'd just dropped and smashed. My priorities were battery life and camera, both of which the Z2 excels at, especially compared to my old Nexus 5. It is not a flagship phone as I buy it for £299 at Argos (contract free, unlocked) but it is still competitive, especially the 21mp camera.
After just a couple of days, battery life is exceptional - about twice as good as the Nexus 5 - and I've had no other problems with it. The construction quality is impeccable.
I'll update this in a couple of months!
5 out of 5.