I think I’m the only person here who has owned the Redmi Note 4 for an extended period. I purchased the device some time in January or February, and while I have had several issues with, it continues to serve me well, and have actually suggested it to a lot of people now that it is even cheaper.
All I can say is that its battery life is exemplary; you cannot kill this thing in a day (because, S625 that leans easy on battery) no matter what a heavy user you are, unless, of course, you do some weird things like subject it to a lot of workload consistently with the aim of draining it. However, I’m not the best of fans regarding how Xiaomi, or the entire Chinese OEM conglomerate achieve their popular battery life statistics. To begin with, when the device was on Marshmallow, it will kill apps and make sure that you do not receive notification unless you open certain individual apps, especially mail apps. In particular, I have been late on work assignments (including today) just because I wasn’t notified of an email in a timely manner. This sucks, to say the least.
Secondly, MIUI is not the best of skins in the wild, and similar to most Chinese skins, it apes iOS so bad I have never seen this kind of obsession before. Functionally, it works, has some cool themes and wallpapers, features and okay fluidity. However, when I updated it to 7.0, apps started to crash unnecessarily, and I’m still not happy as to why they had to strip the update of key Nougat features, which, if you keep tabs on OEM update cycle, was inexcusably late but that is how Android rolls, and we are far from a significant improvement. It is the same narrative we see in politics, where we elect leaders hoping they will do things differently only for them to subscribe to the same model that politics thrives on; “unmet promises” == “we will update your Android in time next year, but you can buy its successor that has newer SW goodies because we lust after your money.”
Ranting aside, you can look for better solutions out here, which includes taking a walk to XDA and picking a custom ROM from the heavily-supported threads for the Snapdragon version of Redmi Note 4. There are cool ROMs for the device, most of them AOSP-based if you are in need of stock-ish experience. I have tried around 5 of them, including Oreo ones that work just fine save for the fingerprint scanner (Goodix). In fact, there is even a Mi A1 ROM for the Redmi Note 4. But (there is always a but, FYI), unlocking the device’s bootloader is not the easiest process as it so frustrating I doubt many people even bother to request for the unlocking tool. It is mandatory that it is unlocked to allow custom modding, and was fortunate to find mine unlocked upon purchase (from Avechi). I will be glad to know if your Xiaomis have an unlocked bootloader as well, as it means that Avechi performs this action for us, which is good. That aside, battery life on custom ROMs is not as good, so take that in mind.
Considering camera performance, I have seen better. While I do not take a lot of pictures in most cases, it serves me well in well-lit situation just like any modern smartphone camera would do. Things take a dip when you get indoors because it takes poor images. I know a poor image when I see one. On the bright side of things, you can load Google Cam with HRD+ that boost quality significantly. It is that good (Google Cam), even on this hardware, but you must have root to enjoy these additions.
Daily performance is okay, but in regard to multitasking, it fails horribly. This is brought about by the aforementioned silly, battery-saving tactics in MIUI. Apps are killed aggressively, which is not fair at all. Anyway, S625 proves its edge as an excellent midrange chipset, and I’m fairly certain this is an assertion shared among many of us.
Most of these setbacks are subjective because I have learnt to live with them. On the whole, though, I have only been slightly disappointed by the device.
Can I buy another Xiaomi? Ha. NO. They make great devices - I mean their hardware is great (btw my power key is toast, unless I press it with my entire body mass), and support for MIUI is okay (they try to send monthly security updates), custom support is great but other than those, I’m not a fan of devices that have to be tweaked so as to work the way I want them to.
FYI: I’m running a custom MIUI 9 ROM based on 7.0 with little bloat and it is, you know, subjectively good.