My 12 year old ionic system finally stopped working. I shopped reviews, cost and availability before finding this one. My house has pets and cigarette smoke inside so a purifier is a necessity! The only issue I have found is the sound! I need to run it on maximum in order to take care of my needs and it is loud! Loud to where I had to move it further away from my seating area. It sounds similar to a window air conditioner on low setting. My last Sharper Image unit was quiet and discreet. This one is neither. The effectiveness seems fine on high but it has also become the elephant in the room.