Actually, I think delivery would be a better option.
Still get a day or 2 to slowly check and try out the phone rather than the short period at the shop.
Global ROM has 4 numbers. E.g. 8.1.0.3
Latest Global stable for 64GB/128GB is 8.2.1.0, 32GB is 8.2.3.0.
If the "Updater" app prompts that a newer version is available, it's a real ROM. Only real ROM can update via OTA.
If it shows 5 numbers, e.g. 8.2.1.0.11, it's a fake ROM.
Go to Settings, About Phone. Tap on "Kernel version" multiple times. It'll launch the Hardware test menu. Run through all of them.
Can bring a powerbank if you want to try if the phone can charge properly anot, and a pair of earphones too.
Thanks weisern, looks like I got a fake ROM then...
Stated as MIUI Global 8.1 (Stable), 8.1.9.0.0 (MBDMIDI)


Haha! 