For about 2 weeks, we have been testing out this new litter box.  Having two cats that tend to go thru so much litter and make such a mess, so far I am quite pleased with this one.  The replacement disposable trays area bit pricey but it is a convenience that is sooooo worth it.  If you're like me and are busy all day and don't want to come home to a skinky litterbox and you don't mind the expense of the refills it's a great product.   We will continue to use it.