This is the first top-filling ultrasonic humidifier I've owned, I've previously used many bottom fills and still own two.
On high mode, with level three heat, this thing puts out a LOT of humidity for such a small unit. The 1.7 gallon tank has emptied in less than a day during my first uses if the room doesn't get to the target humidity. (remember when you first start using a humidifier it also has to add moisture to the carpet, furniture, walls, etc).
The touch controls are simple enough, but a little difficult to read in dark areas, but the remote can help with that.
Filling is simple, whether you take the tank to the water or bring the water to the tank. If you move the tank, there is no seal on the top so if you're instead you will spill. After the first two times taking the tank to the sink, I've found it much simpler to just full the tank in place.
I've yet to actually need to clean the unit but it dismantles into pieces quite easily, everything just resets in place. When it comes to an actual deep cleaning, the air output from the fan is well up the side of the unit, away from the places you'd be spraying water for cleaning so it will be much less of risk you'll get water into the electrics and damage them, I've ruined two humidifiers that way before.
In sleep mode the control panels lighs go off so it's completely dark, then come on for a few seconds if you press a control button. The fan also and output setting also go to low automatically. You can easily press the controls to re-enable high-output in sleep mode but I wish it would remember the previous sleeps settings and use them again.
Sleep mode is very quiet, the normal mode is as well, but the fan does make a faint but noticeable buzzing sound. It's easily overcome with just about any other sound source but if you want complete silence you'll definitely want a lower output like sleep mode.
About noise... as I mentioned this is my first top filling ultrasonic and it's really nice to not have the intermittent "glug glug" noise as water leaves and air enters the water tank. The top fill valve is more complex but has been reliable and completely silent, which far outweighs the slightly louder buzzing of the fan. Ill take stead, low-volume sound over the louder, intermittent sound any day in the bedroom.
The materials are nice enough, it's plastic. What more can I say. The controls are touch sensitive, no physical buttons that click so if you're working in close proximity to the thing you could accidentally change a setting if you don't lock the keypad (three second button press for this mode).
The heating mode is the warmest mist I've encountered in an ultrasonic unit, it's not as hot as a vaporizer unit, but it definitely won't be cooling the room at all.
When you take the top off to fill the tank in place, the directional nozzles come off as well, causing vapor to just pool around the unit instead of being projected away from it. I don't think this short-term self-misting would be an issue but it may be worthwhile to turn it off for the 30s it takes to fill the tank.
If I could request changes they'd be:
-a little more acoustical insulation for the fan
-the nozzles should stay in place when the top is removed
-a soft, press-fit type lid for the water opening when I want to carry the full tank
Overall a good value and if I had a need for a second unit this would be an easy re-purchase.