As an allergy sufferer, this air purifier has been a godsend! If I could give this purifier more stars, I would because it is that good. 
The purifier is quiet and cleans the air so much that it stays clean! When I initially tried it, the meter read the air as 87 percent and less than perhaps 15 minutes or so, it was at 100 percent and has pretty much stayed that way. Now I wake up without congestion, itchy eyes, cough, etc! 
The purifier doesn’t take up too much space which I like. It would be cool to see other colors, too. I just move it to different rooms and it’s been great!
Previously, I had a a purifier yet it was too loud and took forever to work. Not with one. I have since recommended it to others to try out.