Summary: It is relatively quiet but does gurgle if you place it near the bed. For some that could be a relaxing sound. Cleaning should be done weekly even if your water is generally clean. I found a brown residue at the bottom of the unit. I am not convinced that the steam is bacteria-free.
Summary: I bought it since my sinuses were suffering; the radiators here have had the steam valves soldered off so it's straight dry heat, no steam. My hygrometer read two dashes (no moisture) and I woke up stuffed and miserable. This humidifier brought instant relief. (There is another model with a thermostat and automatic cut off, I suggest you buy that one if you plan on using it overnight.) Other than that, it's almost quiet and starts to work almost immediately.
Pros: Adjustable Settings, Easy To Use, Lightweight