Arrived with a wobble in the fan, but thankfully useable while we suffered through the California wildfires (we live in the Bay Area). Our small house is less than 1300sqft, but the purifier struggled to give us even "orange" (middle) air quality in the living room, which is about 500sqft. Finally managed "blue" when the outside air quality returned to normal. Unfortunately, it took a long time to get my replacement unit shipped. If I had to do it again, I would buy 2 45i purifiers for about the same price of a single 75i, so we could spread them around. Unfortunately, I don't feel good about making a return under the satisfaction guarantee, since it was my choice, so will keep what I have.