I put it in approximately 50 square meters, living room, kitchen, and one bedroom in medium mode, quiet unless you are compulsive, with 6 drops of aromatic oil I got 18 hours while the machine itself says 12 hours (unless it means in maximum mode). I am quite satisfied until I see the durability of the product.

I have it in a space of about ~65 sqm with a little help in air circulation (window or air conditioner) it goes everywhere. I have it permanently on maximum operation and you can't even hear the fan, it only makes a sound when it's completely quiet. The color is slightly darker compared to the photo and the size is a bit compact compared to the photo. I am very satisfied.
update: 28/06/2023. It still works!