I really enjoy this air purifier.  I had been looking for one, for awhile, and it just so happened that I was able to get into this Influenster!  I really love how clean the air seems!  I have 3 cats and it is very hard to feel like everything is clean, when you have cat fluff floating around.  The system is pretty sensitive, but in a good way!  I also have a humidifier in my room that I need to use, due to bad allergies.  Anytime I have them both on at the same time, my Shark air purifier air quality percentage tanks!  Of course this is on the nose when it comes to how a purifier works.  The only caveat that I have with the air purifier is that when you go to adjust the filter on the bottom of the machine, you turn it to lock it in place, but if you put it on a surface and turn it at all, it will unlock you filter, so just be careful!