This machine works really good to clean out the air around you, but the only big cons is the price. It is $500 machine and compare to the other one from wal-mart and k-mart, this is the one cost more than 3 times on the price. The only thing I can convince u to buy this machine is 5 years warranty. Anything worng just bring it back to sharper image and they wil give u a new one within 5 years under normal use and regular cleaning.