Basic differences are as follows: 

• Xiaomi.EU (Fastboot) = Forum Custom Firmware, no OTA Updates (manual), Saftynet Passed, Widevine Level 1 usually, Multilanguage
• Xiaomi.EU (TWRP) = Forum Custom Firmware, OTA Updates, Saftynet Passed, Widevine Level 1, Multilanguage
• Xiaomi Global Firmware = official Xiaomi Global Firmware, OTA Updates, Saftynet Failed (in the new versions, therefore no Google Pay), Widevine Level 1 usually
  
• Xiaomi China Original = official Xiaomi China Firmware, OTA Updates, Saftynet Passed, Widevine Level 1 usually, only Chinese + English language

What does no OTA updates (manual) mean for Xiaomi.EU firmware?

- With the Xiaomi.Eu firmware, you download the firmware to your PC, connect your PC to the smartphone, put the smartphone in fastboot mode (volume down + hold power button until the Mitu male appears) and then you can flash the custom rom. There is the first_install file (for Windows, MacOSX, Linux) with which you install the Rom the first time or the update file (for Windows, MacOSX, Linux) with which you can update the system every time. During an update no data is lost, everything remains, only the software is updated. 

What does Saftynet Failed or Passed mean?

- The Saftynet test checks whether the device is also intended for banking apps such as Google Pay. If the test fails, Google Pay will not work. Other banking apps might not work either, but that depends on the app. Kontist or ING Diba do work, but DKB refuses the service. 

What does Widevine Level 1 mean?

- Every smartphone comes with a Widevine level and this is important for encrypting streaming data. Usually, Netflix, Amazon Prime or Disney+ require Level 1, so everything works without any problems. If a device has Level 3, which can happen with China smartphones, it cannot see the content at all or with Netflix, for example, only with 480p resolution. 

Does the Xiaomi.Eu Rom also get updates as long as the Global Rom?

- Yes, usually even longer, because the Xiaomi.eu is based on the official China Rom. This usually comes faster and often has features that the Global does not offer. Xiaomi.eu unpacks this, adds the multilanguage strings (languages) and a few mods and actually releases these on the same day every time Xiaomi does it for the last 10 years. 

Which Rom is the right one? 

- You can't give a blanket answer to that. If it is important for you to receive constant OTA updates, you should choose the Global, knowing that Google Pay will not work. If functionality is more important to you, you should go for the Xiaomi.eu Rom. The advantage is that both are usually based on the stable firmware, which usually gets updates every few months and becomes rarer and rarer over time. As with all manufacturers, there are a few FIX updates in the first few weeks, then only every few months. And don't worry, if it's May and you don't have the May security package yet, the world won't end and your smartphone will become a holey cheese where any hobby hacker can rule the world right now. 

Can I flash the Xiaomi.eu Firmware by myself?

- Of course, it is pretty easy. We got a nice tutorial for that on https://tradingshenzhen.com/en/content/how-to-tutorials