These litter trays (and the whole ScoopFree system) have made my life easier, and my cats happier (they no-longer are fussy like they were about using traditional litter box). I appreciate that they have this option for dye-free crystals---one of my cats has a past history with bladder infections, and so he is sensitive to dyes, perfumes etc....The clear crystals also make it easier to monitor for changes in color of output for cats who are prone to issues. The crystals are very absorbent, and even without scent still greatly reduce the smell you normally would expect to have with a cat box. The cardboard tray holds-up well for the full duration of use (no moisture/ leak issues), and the included lid. makes it very easy to dispose. Great product, and so much easier (and less smelly) than other litter options.