[Xiaomi Poco F1 Questions & Answers] shailendra1993:
I have used Redmi 2, Redmi 2 Prime, Redmi Note 3/4/5, Redmi 3S/prime and only Redmi 2 and Redmi Note 3 as my daily driver.

Those things taught the following:

Don't except updates from Xiaomi, not even security patches, although they have started providing patches on Note series but they are always late, so patches may arrive but not when you expect them.

You may not get the latest features even if you have the latest android version on your MIUI, why? because Xiaomi wants to provide same features to all the phones so that phones running on Kitkat will have the same feature as phone running on Oreo, this makes their software development easy, that means that the feature that you are using doesn't have native support and may be buggy and battery hogging.

There are two channels in MIUI - Beta Channel and StableChannel. Stable channel update is provided every 4-5 months or whenever they feel like or to fix a very important bug. Beta channel was previously bimonthly but I have heard that now, it's changed. Due to this, they don't fix bugs properly and instead introduce more bugs in the system

Their update size are generally 500MB-1.5GB but the fixes are things like: Calender icon changed, Button of some subforum in MIUI forum app changed, New Ringtones and every useless things, then in the end *Bug Fixes* but they don't mention which one. Out of every 10 beta updates only 1 or 2 updates are useful while others are just formality.

Now, note this, other companies give update to keep your phone running for longer amount of time. Xiaomi thinks different, they will wreck your device with every update they provide.

When I had Redmi Note 3, Beta channel was more better and more stable than the Stable channel, I am not lying go check the forums.

There is no major change in MIUI 7-9 the first major change I saw was MIUI6 - MIUI 7 after that all changes were just useless and they everytime just change notification shade style.

MIUI 10 - Notification shade now looks like a copy of iPhone and it's really very cheap act by Xiaomi, although their App switcher is somewhat cool.

Custom ROM:

Xiaomi phones works best with stock android and indeed has the best development support. But there are few catches.

Not all features work in custom ROM, you will have to leave one or two things if you want to use custom ROM.

The famous and best developers will not port VOLTE if their cell providers don't provide it

Camera (on Xiaomi phones) doesn't works well on custom ROMS.

Xiaomi does provide kernel but they don't provide a lot of proprietary codes and binaries that ensures smooth functioning of phones.

Don't buy the phone if you want to get updates unless it's Chinese, they do care about Chinese people unlike their global counterpart, or those people who develop global roms are arseheads.

All the above points can be confirmed on MIUI forums and XDA, if anyone says that even one of the point(s) is wrong, he is probably new in Xiaomi's world.

Redmi is the cheap line and they get late updates and bugs are not fixed properly. Mi is the expensive line of Xiaomi so they get proper update in first few months and after that they are also neglected. Since Poco is also a cheap but is a flagship, they will get good number of updates and fixes for few months then they will announce another phone and Poco will be neglected, and people who are saying that Poco has a different team may be wrong, I don't think Xioami will divide the team because internally it uses the same MIUI as others only launcher is different. For world Poco is a brand, for Xiaomi it's yet another phone.