The update is available via PC Companion/ Bridge for Mac applications. You can also try looking for it over-the-air by going to Settings > About Phone > Software update.
As you can expect, the update includes KitKat specific changes like UI improvements, performance enhancements, Cloud-print support, and new version of Hangouts and Downloads apps as well as Sony-specific features. Full change-log can be found below.
- Google’s Android 4.4 KitKat: bringing performance & UI optimisation
- Tweaked Status Bar and Quick Settings
- New launch animation and live wallpaper across the lock and home screens
- Better storage choice: Option to easily move applications from internal memory to SD card
- Updated native app portfolio with tweaked / improved / current experiences
- Support for Xperia Themes
- Compatibility with SmartBand SWR10 and Lifelog app
Source: Sony
