When I lived in an apartment I bought one of these because the upstairs neighbors (4 of them) smoked virtually ALL DAY LONG. It came through the plumbing (crazy but true) and just stunk my place up something fierce. The Ionic Breeze took the cigarette smell right out of the air. There was a faint smell of ozone (the smell you notice after a lightning strike) but it's not that bad.
All in all I like it. I like it better not living in that apartment but that's a story for another thread.
EDIT: FYI -- You have to turn it off if you're going to burn candles. The oil from the candles will just gum up the filter element in the breeze.