I spend a good amount of time online doing research and seems like the best value for its function. I find nothing wrong with this product. And I have it in my bedroom for months now and it works really good. I have a cat and lots of hair trapped in the pre-filter. I used this daily, medium on daytime and I set it on night mode during my sleep and it goes back to its setting after 8 hours. This is an excellent air purifier for me.