5/6 cats use this litter box more often than their open box at the top of the stairs. I think having the two entrances reduces their concerns about getting ambushed on their way out. I do not notice a significant increase in odor compared to their open boxes. The cats were not really using the top portion of the item until I added some peel-and-stick felt to the slippery wood top. I would purchase this item again and prefer this design (as do the kiddos) to the similar 53" Kimmel item with the round drop-in hammock type bed. 

*honest review collected due to $5 offer to do so.