I bought this purifier 5 years ago. This little guy has done wonders for air quality in my home. With 2 dogs, 3 cats and 2 kids, it is invaluable. I vacuum the filter about once a month, because I can't remember to do it more often, and its probably gone longer than that. I run it all night for ambient noise, and all day so the dogs don't bark at every little thing while I'm at work. If its running, the house really smells clean. It gets a great deal of dust and animal hair out of the air despite my very frequent cleanings. This thing just keeps on going, I'm so impressed. It will stop running if knocked over or filter dislodges, so I trust it when I'm gone. Highly recommended.
I have 2 of these machines in my house. They have made a remarkable improvement in my daughter's allergies and my son's asthma. Reasonably priced, great looking unit, and super easy to clean permanent filter. Definitely cuts back on our household pet odors too.