Android 5.1, the latest Lollipop release, is now landing on the Sony Z Ultra Google Play edition.
A number of Google Play edition devices have already received the Android 5.1 update, and the latest to join is the Sony Z Ultra. The update, which bumps the device to version LMY47D, and comes in at 212MB in size. Android 5.1 brings quite a few changes, including tweaks to the way notification disruptions are handled, a few cosmetic changes, and of course bug fixes.
The update is slowly rolling out across devices currently, so it may be a few days before you see the notification to update. If you have already received the update head into the forums and let us know how the update is treating you so far.
Thanks for the tip, Alcarnor14!