I bought SWMBO a OnePlus One to replace an ageing Sammy Galaxy S3. I'd rooted that and moved it to Cyanogenmod after updates ceased appearing. That's now in the hands of my son, who is happy with it as it plays more games than his Nokia 100 did!
I was so impressed with the OnePlus One that I bought another one for my daughter.
At the time I was using a Sony Z Ultra, but after two screen replacements, and one complete device replacement due to it being very fragile, the last hairline crack in the screen caused me to jump ship from Sony to OnePlus myself.
I bought the OnePlus Two. And I must say it's been brilliant. OxygenOS has proved to be superb with no manufacturers bloatware, battery life is great, and I would recommend it to anyone. While it doesn't have the big brand name slapped on it, the performance and experience is superb.