I bought mine a few weeks ago because me and my wife had both gotten increasingly agitated by dust allergies. I swear I haven't had any trouble since I've gotten this bad boy going. No, it isn't a cure to what ails us in the air but it is a massive help. Not only does the device work well, the brand that offers it's services is extremely kind and responsive. It has been great! Beyond great! The whole experience.
This unit runs on medium full time in a room my two large dogs play in. I never hear it and a there is no unwanted scents from the dogs, dust, or dander.
The air filter is quiet and efficient. I replaced one I had by another manufacturer, which was noisy and kept us awake at Night. However, this one is very quiet. You know it’s on, but it doesn’t make much noise.