MIUI 9 on your device will be updated to its stable version.It's better than the Developer ROM you're using right now in terms of stability and productivity.However, here are a few points you should pay attention to:
1.Automatic updates will be turned off after this update. For next update, go to Settings > About phone > System update, and tap "Check for updates".
2.Your data won't be affected by this update. We still recommend to back up all important items to Mi Cloud or your computer before you start updating to avoid possible data loss due to abnormalities and unexpected errors.
3.Root access will be turned off automatically after you update. (And nothing will change if you haven't been using it in the first place). If the apps you use frequently need Root access, think whether you should choose not to update your device.
4.Stable ROM outperforms the Developer ROM in terms of stability and productivity. Some new features might not be available due to compatibility or other reasons, but this wouldn't affect your overall user experience.
Apps
New - You can uninstall apps in the Settings app now(03-13)
Lockscreen, Status Bar, Notification Bar
Fix - A white panel appeared in the Notification shade(03-06)
Home screen
Delete - Deleted shortcuts for moving data and managing Second space(03-07)
Themes
Fix - The Themes app crashed while importing items(04-24)
Camera
Fix - With XS system font, dual camera watermark was truncated in landscape mode(03-20)
Music
New - All-new current playlist(01-25)
Optimization - Revamped Mi Music(01-25)
Optimization - Managing audio files on your device is much more convenient now(01-25)
Weather
Fix - The Weather app stopped working(03-06)
Settings
New - You can hide the shortcut to Second space now(03-07)
Fix - Issues with proximity sensor(03-06)
File Explorer
Fix - Exiting a folder brought you back to the top of the page(03-13)
Browser
New - Added a card with recommendations(03-14)
Optimization - Improved search bar with bigger input area(03-14)
Game speed booster
New - A column for online games(01-30)
Other
Fix - Yellow pages force closed in some cases(04-17)