This morning Sony began the update process for the Xperia Z2 to Android 4.4 KitKat. According to the documentation, the update should bring along some noticeable improvements including “enhanced call quality” and “improved charging when battery is low”. It’s not clear when the rollout will be complete, but it shouldn’t be too far off so keep checking that ‘System Update’ tab in your settings for KitKat goodness.