Product review (4 stars): Good for a bedroom sized room.
Works great. No white dust like you get from the ultrasonic ones.  Consider the volume of the space, not just the square footage.  We have this in our  MBR that has very high ceilings and it struggles to get the humidity up to 30% when it is near freezing outside, even with the forced air heat off. There's a split system heat pump in the bedroom. Noisey on high, but it is actually great white noise.