It does`nt "Clean" the room or anything. The dust it collects on the grids when they`re full is nothing really. There`s always gonna be dust and stuff in the room, so if that`s why you`re getting it, don`t bother. It DOES leave a certain smell in the air when it`s on though. The fact that it`s totally silent is good too. I just leave it on and forget it.
It was expensive, I forget, maybe $400+ or $500 for both. I`ve had the HEPA type filters in the past, they`re just too noisy and you need to replace filters anyway.