[Xiaomi 12 Pro] MeowMilev:
Here are the main difference between

China ROM Vs EU Rom vs Global Rom

Tested on: Xiaomi 12s Ultra

All known issues that still persist as of June 2023 Miui 14.0.12.0:

China Rom:

1) contacts not at your contact list calling at your phone will always show Unknown Numbers at Notification toolbar

2) AOD display have no option to disable auto turn off if phone prolonged at dark room. So it will always turn off itself.

3) turning off Bluetooth from drop down top menu only turn off 24 hours. This will drive you insane.

4) if you use english, a brief 2 second of Chinese after reboot will show in apps like clock, and calendar app before changing to english. A lot of high end advance settings still have traces of chinese and broken english.

5) And a lot of bugs, crashes, stuttering where china developers never bother to fix.

6) installation of apk have extra security steps.

7) lots of chinese bloatware that cannot be removed. Advertisement in native apps like mi video. You might ask, i can always get vlc. Don't forget, native app functionality is always better because it have better latency! Vlc apk have audio delay! Go see for yourself...

8) feedback all in chinese and they don't read or entertained english complaints.

9) themes and wallpaper are all chinese uploaded community despite changing english.

10) does not support google hands free assistant. ok Google feature will be grey out under settings!!

11) smartwatches you bought globally will not work with playstore global apps. You need to download the chinese version to get it working. For example, Fossil Gen 5e will not work at playstore Wearable App but will work at getapps wearable app.

12)A lot of Bluetooth headset signature compatibility issues. Brands that can't be detected by xiaomi are: Audeze, Turtle Beach, Creative, etc

13) phone crash from app are very frequent. E.g app closing and reopening itself. So is like a 1 second keyboard and app minimized and maximized crash scenarios. At least once every 1 hour from intensive stress testing.

14) very aggressive miui optimization that closes app even when you told them not to. Battery life was excellent.

15) 10 second security delay on unsecure app.

16) system update 1 toogle. Getapps update for your mi apps. And playstore for your 3rd party ones. Can your mother learn this?

17) Torch light that turn itself off in 1 hour. Good luck hiking with it.

18) you can turn off miui optimization and toggle for pause activity in apps are present.

EU Rom:

1)You can't turn off miui optimization, so a few toggle like pause activity only available in off optimization settings. This will drive u nuts as rarely used apps will always need you to grant permission.

2)An active development team that actually fix things. E.g AOD display that stays on forever. Bluetooth that turn off forever from drop down. It will show phone number instead of unknown numbers from notification listing.

3) System update is slow.

4) if you encounter bug in default mi apps like, mi video, messaging, you will need to wait 3 months before it fix. Cause you can't update mi apps via Get apps. Only can update 3rd party apps via playstore.

5) installation of apk have less steps.

6) no bloatware. But still u can find some useless mi app like, mi coin, mi browser which cannot be removed. Advertisement in mi video is also removed, so is wise to use native apps for video because it have better latency!!

7) toxic community and developers that scrutinized your feedback from their forum. E.g their lead Igor is the most toxic developer i ever met. Their tester like gogocar are very helpful and resourceful. Lets hope the war in Russia won't affect their work in the long run if you know what i meant!

8) access to themes and wallpaper are still native chinese.

9) support google hands free assistant. Ok Google features.

10) global wearable apps found at playstore will work with your smart watches.

11)A lot of Bluetooth headset signature compatibility issues. Brands that can't be detected by xiaomi are: Audeze, Turtle Beach, Creative, etc

12) phone crash from app are not that frequent. E.g app closing and reopening itself. So is like a 1 second keyboard and app minimized and maximized crash scenarios. At least once every 3 hour from intensive stress testing.

13) bootloader is unlocked yet the whole rom is still not as flexible as a total rooted device.

14) less aggressive miui optimization that does not closes app when you told them not to. Battery life was excellent.

15) many will choose to go EU Rom, cause at the end of the day, you will hate miui os soo much!

16) 10 second security delay on unsecure app.

17) if you use adb shell command line is now screwed with multiple session that can't be reset to single session no more. There is a emulator user in your rom.

18) straight forward system update that updates all ur mi apps and playstore for your 3rd party ones.

19) Torch light that does not turn itself off.

20) developers hide a lot of features. You can't turn off miui optimization here. And pause app activity toggle is missing.

Global Rom

1) everything in english. If you switch to chinese or other languages, a brief moment of english will show after reboot.

2) contacts not at your least calling at your phone will always show Unknown Numbers at Notification toolbar

3) AOD display have no option to disable auto turn off if phone prolonged at dark room. So it will always turn off itself.

4) turning off Bluetooth from drop down top menu only turn off 24 hours. This will drive you insane.

5) themes and personalized uploads are in english also.

6) support google hands free assistant. Ok Google features.

7) wearable apps from playstore will work with most wearables.

8)A lot of Bluetooth headset signature compatibility issues. Brands that can't be detected by xiaomi are: Audeze, Turtle Beach, Creative, etc

9) phone crash from app are very frequent. E.g app closing and reopening itself. So is like a 1 second keyboard and app minimized and maximized crash scenarios. At least once every 1 hour from intensive stress testing.

10) lots of localized global bloatware apps. Mi video is riddle with advertisement too. So you will have to find alternative app like vlc which has audio delay latency issue in movies.

11) very aggressive miui optimization that closes app even when you told them not to. Battery life was excellent

12) 10 second security delay on unsecure app.

13) realtime updates from getapps and playstore.

14) Torch light that turn itself off in 1 hour. Good luck using it.

15) you can turn off miui optimization.

So in the end what can we learnt and summarize? Miui os is no doubt the worst android operating system in the market when in comparison to samsung one ui.

So which one would you choose? You should choose EU rom. Cause at the end of the day, is about functionality. 1 key difference is that EU Rom AOD display will have the option to stay on forever whereas the 2 other rom does not! This is a deal or no deal breaker when comparing operating system! So, better not buy xiaomi to begin with! End of story.