"A huge tank and smart sensor can't hide its fatal flaw: no water filter."
The 9-liter capacity means this humidifier can run for more than a full day on high, but because it's an ultrasonic unit with no filter, you must fill it with expensive distilled water to avoid coating your room in mineral dust.
This is for someone on a strict budget who needs to humidify a large area and is willing to exclusively use distilled or reverse-osmosis water. The combination of a large tank and external sensor is functional for plant rooms or other controlled environments.
Anyone planning to use tap water should avoid this model. The ongoing cost of buying distilled water will quickly erase the upfront savings, and the cleanup from the resulting 'white dust' is a significant chore. It is not a convenient set-and-forget appliance.