I'm Sold!
I purchased one of these on ebay.  I honestly didn't think it was doing anything until I had an issue with allergens in my home.  I would get headaches when working in my home office.  I had this unit in my bedroom and there was a noticeable difference in the air quality when I entered the room.  I'm sold!  I also have a Holmes floor unit, the GermGuardian is smaller and works better than that unit and has no filters to replace!  I plan to get a few more of these.
Rating: 5 stars