I have used many humidifiers over the years, and so far this is my favorite. The controls on this unit remind me of my old TaoTronics, but it functions seem better. It is much quieter when operating, and when it shuts off after reaching humidity level, it is inaudible (other humidifiers, like my old Air-O-Swiss made noise the entire time they were turned on -- even after reaching humidity level).
The top is easy to fill and is in large part why I purchased this unit. I will never use a bottom-filling humidifier again. I like that you can reactivate the heat mode when in Sleep mode to add some warmth during the night. The warm mist option is another reason I chose this unit.
One big improvement over my prior TaoTronics (I had 2) is that turning the unit off REMEMBERS its settings when you turn it back on. Seems like a small thing, but units that forget are a nuisance.
One small nit is that the humidity reading on the unit seems about 8% high compared to my weather station and multiple humidity monitors. But that's easy enough to correct for. I also wish the buttons didn't beep quite so loud -- the LED indicators are more than adequate.