I've had my unit for nearly 5 months now. Originally purchased as I suffer from hay fever and I usually react to my dog in the warmer weeks in summer. So far the unit has been brilliant, it filters the pollen, pet dander and other particles that would normally set me off. Also being small you can move it from room to room easily and as it has a HEPA filter it gets to work straight away. It wouldn't be ideal for a very big room, that's something you have to be aware of, but for the price you can't go wrong, it's certainly worked for me!