I once bought the OnePlusOne because it was 1/3 of the price of an 64gb 5,5" iPhone 6.
Build quality was ok but the software was such a mess. Two OSs and non of them was really supported. Constant app crashes and weird behaviour/stutter. Call quality was pretty bad too. Changed back to iPhone as soon as possible.
Yes but the OnePlus 3 is huge jump, they are getting better every year tbh.
I think this Xiaomi Note looks interesting, but note for me. The Mix looks truly innovative.