In a blog post dated October 6, 2015, Sony announced their upgrade roadmap and plans for Android version 6.0, otherwise known as Marshmallow. The update would be rolled out for the following devices: Xperia Z5, Xperia Z5 Compact, Xperia Z5 Premium, Xperia Z4 Tablet, Xperia Z3+, Xperia Z3, Xperia Z3 Compact, Xperia Z3 Tablet Compact, Xperia Z2, Xperia Z2 Tablet, Xperia M5, Xperia C5 Ultra, Xperia M4 Aqua and Xperia C4.

The October 2015 update was an experimental Marshmallow concept called Concept for Android. Essentially, the beta scheme allowed Xperia users to test software builds for their phone as the concept stages progressed. During the Lollipop release, Sony allowed their users to trial the software as well. It seems they decided to do the same for their Android Marshmallow update.

Sony only opened the beta to 10,000 users of the Xperia Z3 and Xperia Z3 Compact users in Denmark, Estonia, Finland, Germany, Iceland, Ireland, Latvia, Lithuania, Sweden and the United Kingdom. This meant that only users of those phones were able to test the concept software.

In February 2016, Sony launched a new beta called the Xperia Beta Program for the Xperia Z2, Xperia Z3 and Xperia Z3 Compact. This update was made available for users in Italy, Netherlands and Spain. The difference between this version and the previous one is that the latest is so much closer to the final version that will be released to all Sony devices soon. This update was released for the Xperia Z5, Z4, Z3 and Z2.

However, the Xperia Beta Program seems buggy. This March, Sony informed users that complaints will hopefully be addressed in the next release. Two issues were brought up: the Double-tap to wake feature issue and the audio-related problems. The former wasn’t working 100% and the latter occurred when using Bluetooth devices.

The audio-related issue also seemed to exist with the concept program running on a Sony Xperia Z5 as mentioned by a user on the Xperia blog. According to the user, the update “rendered my Bluetooth audio virtually unlistenable with constant crackling and distortion.” The good news is that Sony is aware of the issue and is already fixing it for the Xperia Z2 and Z3. Issues with other models will also hopefully be addressed.

Android 6.0 Marshmallow features Now on Tap (where you can get cards featuring useful information), a better battery (dubbed as one that “works smarter, not harder”) and better control and security.