I have only a had a few minor annoyances with the software, but everyone has those so it doesn't really bother me. The build quality is ******* amazing, I actually got that case from vivo while it is not the best looking, it works lol.
I have been able to take some pretty damn good pictures with this phone as well. I especially love the monochrome sensor.
I got mine from Sprint not essential so I have zero manufacturer defects and if a problem does arise sprint is who I deal with. As far as essential customer service, I have reported the minor annoyances and have generally got a reply fairly quickly.
I was super unsure of this device when I got it after constantly reading the forums. I can say that I will not be returning this device, at the end if the day I get crazy battery life out of this phone. The screen is amazing, I don't have to deal with stupid expandable storage. You get updates on the reg, with little waiting. Also through sprint I will only pay 520 bucks for the phone as well.