It's a keeper.
I must admit I was skeptical. It's sitting right next to the cat's litter box and I notice a HUGE improvement.  It does make a whirling noise that if it were in my bedroom would probably bother me but the family hasn't said anything about it so I give it the full 5 stars.  Night light is a bonus.  I love my two cats, but don't love the cat box smell.  Worth the $.
Rating: 5 stars