It was not too long ago that OnePlus began to kick off its soak tests of updating to Android 6.0 Marshmallow for the OnePlus 2 (aka the 2016 flagship killer), hoping that in the soak test, the limited number of users exposed to the Marshmallow build will be able to keep a keen eye out for bugs and the ilk. It looks as though the time for soak tests are now over, as the OxygenOS has picked up its beta Marshmallow build for everyone, albeit not via Over The Air (OTA).
Basically, one will be able to download and give the beta build of Marshmallow for the OnePlus 2 a try, where it carries the name OxygenOS 3.0. You will have to manually flash it however, since as mentioned above, it does not come in the form of an over-the-air update. This is due to the fact that OnePlus intends to be careful with its release, hoping that it will be a bug-free experience by the time it arrives in the form of OTA.
Well, at least we do know that this build will get its airtime via OTA in the future. Needless to say, the new software will boast of all that one can expect with Android 6.0 Marshmallow, in addition to other stuff that OnePlus has planned specially for it, including a brand new OnePlus Camera UI, a new wallpaper picker, better Shelf UX, general performance improvements, speedier fingerprint scans that won’t leave you tapping your feet, and March security patches.