3 out of the 4 of us are sick with the flu. This air purifying machine has been working non-stop. We did achieve 100% clean air before sickness hit us. The photos show how much this machine is working for us. The percentage dips low and the fans kick up on high to try and keep our environment fresher. 
I do like that the display can be dimmed. I would like for the machine to be quieter. Although it does sound like a fan would if you sleep with a fan on. We like silence when we sleep. 
In summary, the air purifier works hard to keep your environment clean, it is a bit loud when the auto setting ramps up the speed, and it is easy to clean. I love the easy set up. The machine is user friendly. The filters on the sides pull out easily to clean off. I am happy with my free product I received in exchange for my honest feedback.