Over the past few months, Sony has been making great strides in keeping their phones up to date with major Android releases as well as the monthly Android Security Update patches. This month it would seem is no exception. The Japanese company has rolled out the December security update to the Xperia XZ, Xperia XZs and the Xperia X Performance.
The update is firmware build 41.3.A.2.24 for all three devices and the update is hitting unlocked phones first as you likely suspect. The update is small, less than 200MB, so it is a quick install but does require a reboot of your phone once you have it downloaded and installed.
With the patch size so small, you can probably summarize that there isn’t much else in this update beyond the Android Security update patch and you are right. Sony did not indicate any other changes or improvements in the release notes for the updates. That suggests there are not any (unlikely) or a handful of small tweaks to performance (likely).
If you have the Xperia XZ, XZs or the X Performance, you should see this updated firmware come to your phone over the course of the next few days. You can try to check for it manually in the Settings of the phone if you want as well.
Oh, and for those who have been looking at the Xperia XZs, it is down to $499 on Amazon, a $100 savings. It is unlocked and works with AT&T and T-Mobile here in the US. The Xperia XZ is $399 while the Xperia X Performance is down to $392.