I have a OnePlus One, its a great phone, the quality is nice. I find battery life can be on the shorter side compared to my old galaxy note 2. Its sturdy build though.
Some known issues, and an issue I am currently facing, the screen can become unresponsive in places. And either its a loose wire, and an easy fix... or not a loose wire and a complete write off (unless insured, or you are happy for a full screen replacment)