Based on my experience so far with the recently purchased LunaPure Air Purifier, I give it 5 stars. Set-up was easy. It is quiet, even if when on auto mode it appropriately increases fan speed. The small size of the unit makes it easy to position. That it discharges air up rather than to the side is a desirable feature, reducing any concern for us about it affecting a room thermostat or heat pump. The air quality indicator with percent clean air is good feedback. The washable pre-filter with a 2nd one to swap out should prolong the life of the major filter. It fulfills its advertising and should be an improvement over the purifier it replaced.