This gadget has three fan modes, and all of them are basically useless.
Fan mode 1 is very quiet, which is good when you sleep, but the air flow becomes so low that it barely purifies any air. Already on fan mode 2, it starts to sound so much that you do not want to be in the same room for a long time. It would have needed a position between 1 and 2 that can be used during the day without disturbing too much.
The auto mode usually goes to mode 1 but sometimes increases to mode 2 when the air gets dirty, which is a perfectly OK behavior. The allergy mode usually goes to position 2 but increases to position 3 when the air becomes dirty. This mode sounds too much for me to want to use it.
It is also possible to run it manually, but with the same problem as above. However, it is possible to drive it in position 1 at night, the display goes out automatically when it gets dark, which is good. However, 6 keystrokes are required to switch between positions 2 and 1.
When it gets dark, it automatically switches to "night mode", which seems to be identical to the auto mode but with the display off. It works to sleep as long as it does not feel any dirt, because then it immediately starts to sound more. It should always be quiet at night.
Wifi is fun but hardly necessary. It is good that you can see the time until the next filter change. The design is smooth with a practical carrying handle. The base is quite small so it is a bit wobbly. Physical buttons would have been better than "touch buttons". However, there is a child lock, which is good.
Had there been a fan mode between 1 and 2, it would have received a higher rating from me.