Is Oxygen really that bad then?
In the first couple of weeks I found it fine, but once I started properly settling with the OP2 and doing my daily habits, the issues became more noticable. The device lags for a few seconds after wake, which only crops up after a day since bootup. There were also random freezes as well. Also, the way they implemented the hard keys/soft keys doesn't seem to properly report to apps which keys are in use, meaning if you're using software keys, they sometimes don't properly hide or with Snapchat the keys overlay the actual app, and with hardware keys, apps fail to display the 3 dot menu button. This was my main issue with Oxygen OS, which became pretty annoying to use. The Marshmallow beta does better, but there are still some bugs.
Apparently there are rumours that Oxygen OS and Hydrogen OS will merge later in the year though, so hopefully that will provide a better stock ROM for their phones.