Hi, we bought 4 of these units - 2 of the larger ones and 2 of the smaller ones. All 4 units have performed exceptionally well and we have notified significant improvement to the air quality in our home. We compared them to several international models and found feature wise to be on par or slightly better. Would definitely recommend them in bedrooms and large family areas. Our sleep has also improved. Very quiet in auto mode. Very happy to recommend.