The few remarks concern:
A bit of noise at night when the water starts to boil, but it must still have sensitive sleep
Beware of burns with water when handling the unit in operation, for example, to move or to recharge it while it is almost empty.
Take note of how to maintain it to avoid a proliferation of bacteria in the unit when not in operation, but this is true for all humidifiers
After a month of use I just bought a second because I find them very effective.