The new update brings along many changes and enhancements, such as Material design UI, improved lock screen, functionality to transfer application to the microSD card, multi-user support, guest mode feature, and much more.
Although Sony has not given its confirmation yet, but there are chances for the older devices such as Xperia ZL and Xperia Tablet Z to receive the update too. It is an OTA (over-the-air) update, which means that the Sony PC companion software will not come handy for updating your device, as it won’t pass notifications, so keep checking your phone instead for the update arrival. With this new update, the build number will change to 10.6.A.0.454.
The update for the Xperia Z is 694.8 MB in size (as shown in the image above), it would be better to download the update on a stable Wi-Fi connection. If you don’t have a Wi-Fi connection, then go for a big data plan so that the update downloads smoothly without data loss. The update has already started appearing on many devices, however, depending on the region you are in, it might take some time to reach your device.