Overall, a good transaction, except for...
I am fairly happy with the unit. It does a good job in our 3000 square foot house, with the two dials set about half way. It arrived on time, in good condition. However, as others have stated, it is a little on the noisy side, even at the lowest setting. But we run it when we're not in the room and the clean air gradually fills the house. Second, the O3 output was too strong, even on the lowest setting. I removed one of the two O3 cards and it's good now. My third dislike, is that the filter for this unit has both the hepa and charcoal filters combined. You CANNOT wash them, but you could vacuum the hepa filter. Fourth, I have been unable to find the replacement filter to buy. However, the slightly good news about the filters, is that I bought the separate hepa filter (it's an exact fit) and the charcoal filter (it's a fraction smaller) and I plan to use them instead. I can see why this one has the lowest price of the larger units.
The ultimate test: yes, I would buy it if I had to do it all over again.
Lastly, the third photo they have of the unit, with the glass sides, is NOT accurate and it's for a different filter.
I hope this helps you make an informed decision.