I purchased this unit to keep my house clean during some home projects while contractors had to enter my home. I liked the peace of mind of the unit to keep my home clean. My only suggestion would be to make the unit default to always use the auto setting, I just leave it on that all the time. I do not see a purpose to leave in manual when the unit auto detects how clean the air is and then adjusts.
so far we are very pleased with our air purifier. we are elderly and still like having family over (in small numbers) and we have a dog so this helps us clear the air of germs, bacteria and dog dander
After two weeks I am totally sold on this item ... COmparing ones I had in the past it is wonderful .. easy to clean and very quiet .. controls are right there to adjust and just see it working ..