I chose this camera for monitoring the front part of my house, as it was affordable and had good reviews. After installing it, I am sharing my comments as well.
1. Very easy installation, as the package contains everything needed (screws, mounting tape, cable, charger, and even a sticky guide for where to make the holes in the wall).
2. Easy and immediate connection to the Xiaomi app (Mi Home). I didn't scan any QR code or anything. As soon as I opened the Mi Home app, it found it immediately. The connection was made via Wifi (the camera also has the option to connect with a network cable). Regarding the signal range, which I imagine concerns many, I will say it has from very good to excellent signal. It was installed on the exterior wall, where exactly inside is the router. It has an immediate response to the movements I make through my phone, and I have had no disconnections so far. Also, before installing it, I tested its range on the back exterior side of the house, where the router is now about 10m away, and again the signal was just fine. So I summarize that it has been tested by me at a distance of up to 10m with an external wall intervening. The router I have is the one provided by Vodafone for their 100 Mbps VDSL connections. Also, it connects only at 2.4 G and not at 5 G.
3. I installed a 256 GB microSD card (https://www.skroutz.gr/s/38513098/Sandisk-Ultra-microSDXC-256GB-Class-10-U1-A1-UHS-I-me-antaptora-150MB-s.html) which activates the camera's ability to record data (essentially motion) and store it, without requiring a subscription to Xiaomi's cloud. You can set it to record continuously (and save it to the microSD) or only when it detects motion. You can also choose between human detected or motion detected, and thus depending on your setting, the camera records. I have chosen human detected, and when it sees a person in the area I have it monitoring, it follows them, records the video, and sends me a notification (and you can activate or deactivate this). When the person goes out of the camera's field of view, it returns to the initial position you have set. To define the area you want to monitor, you simply manually turn it with the arrows towards the area you want. Whatever the camera sees in the direction you turned it, that is monitored. You can also create some Automations, meaning you can set that for example "if you see a person in the area you are monitoring, between 12:00 and 06:00 send me a notification and activate the voice alert." In general, it has a lot of settings, and I am still exploring them, but overall it is easy to operate and does what it promises, monitors the area, records for free, and sends you notifications.
4. The image quality is perfect in daylight and up to dusk, even at distances of 10-15 meters. In complete darkness, the image looks as if there is light, but the quality drops dramatically for distances over 10-15m (meaning you will barely recognize facial features). However, up close, everything remains flawless. Overall, I am satisfied because I want to know what happens in my yard in front of the house (3-4-5 m) and not on the entire street in front of my house (10-15m).
In conclusion, I am completely satisfied with my purchase and will likely choose another one for the back facade of my house since the wifi signal is good.
If I had to mention one negative, it is that its charger is quite large (larger than the classic fast mobile chargers), which made it a bit difficult for me to fit it inside a waterproof wall box to safely make the power supply connections and also to look nice on the facade of my house. Nevertheless, in such a box https://www.skroutz.gr/s/27134899/Aca-Ilektrologiko-Kouti-Exoterikis-Topothetisis-Diakladosis-IP44-me-Lasticho-gia-Stypiothliptes-83x83x43mm-se-Gri-CHroma-GR17053.html it barely fit along with the connection terminals and the remaining cable that was left over.