One of the major selling points of the OnePlus One series was the inclusion of CyanogenMod right out of the box. This year OnePlus decided to grab some top developers from the Paranoid Android team to build their own version of Android "OxygenOS". The great thing about the OnePlus 2 is that it is incredibly developer friendly. You can easily root it and get a custom recovery installed.
Once recovery is installed you can flash whichever cusotm rom your like. There is now an unofficial build of CyanogenMod 12.1 available for download. This build is surprisingly usable. Working in this build are a booting OS, working display, touchscreen, camera, audio, RIL, Sensors, Wifi, Bluetooth, and GPS. Their are a few bugs including fingerprint scanner, laser autofocus, notification slider, and enforcing selinux.
The lack of fingerprint support alone would be enough to detour me, but if you are interested in a stock vanilla AOSP experience more than you are a fingerprint scanner this could be right up your alley.
XDA