I have been using the purifier for a few weeks and I must preface this by saying I’msitarasquare an air purifier user from WAY back:  I sleep with one on every night and have for the last 6 years or so.  So I’m a tough cookie to please.  Here’s what I like about theirs:  It’s got three speeds which are helpful for noise and the lowest two are very quiet.  Even on it’s loudest the sound is soothing and consistent, very easy to sleep with and doubles as a great white noise machine.  We live in LA where pollution and dust come into the house easily but I must say the room I have the purifier in seems less dusty!  I also love that it doesn’t blow huge amounts of air (which can be drying or too cooling).  All in all I’ll give it a definite THUMBS UP.