I am really happy with this litter box.  It has so many great features that any person that has cats would love.  It is so easy to set up and it helps reduce the amount of scooping the litter box for weeks. It scoops the litter beneath a waste trap, so this reduces the smell and keeps the tracking very low.  Each crystal tray can last up to a month (with 1 cat, which I have).  The tray is easily removable.  My cat likes it and I like that it doesn't smell, isn't dusty, and doesn't track litter all over.  The best part is not having to clean it every day.  This is a really great litter box all around.