My allergies were worse at night. Now the air in my room is fresher and I don't wake up all dry from mouth breathing so much. It is quiet enough on the medium setting for sleep, The high setting with the UV light on does prevent sleep for me, but I leave it on those setting during the day, so I still get the benefit.  

(optional) Example: Great value, easy assembly, durable finish
(optional) Example: Not enough color options