I've had this Honeywell Insight Air Purifier for a few weeks now.  I put it in the room near the cat litter box to help keep down the smell, and it's working great.  My wife's office is also in that room and she doesn't even notice when the cats are using the litterbox anymore.    There are multiple settings, but we can actually keep it on the lowest setting and it keeps the room smelling fresh.    The high setting is a bit loud, but it can really pull the air through if you need it.   We actually did put this in the kitchen one day when we had some smoke smell from some ill-prepared food, and it cleaned that smell right up within minutes.    So I'm quite happy I've got this, it's working great and I can recommend to anyone looking for a good room air Purifier.