So glad I bought this for my bedroom.  My sleep, which is compromised by having sleep apnea and using a CPAP, has noticeably improved with the use of the 311. I keep it on 24/7, using everyday mode 50% of daytime, boost mode the rest of the day, and sleep mode at night. Really appreciate that the light goes out and it is basically silent on sleep mode but still working. It is also nice looking and very simple to use.