Well the draw back of this litter is it really starts to stink after awhile. I've got only one cat using it, she pees in it once or twice a day, but not every day (she uses the other boxes too) and uses it for pooping maybe twice a week. I, like always, scoop it as soon as I find anything in it.
The litter is extremely efficient, even after one month I have not had to add any fresh litter to the box. However, even though it seems to clump well and scoop clean, it is starting to stink. Not like pee, but an icky smell all the same.
I do like that Queen Eva rolls in it and is not covered in dust after, but the smell is bothersome. I hate the idea of dumping out what appears to be an entire box full of what appears to be perfectly good litter. but what the heck is that smell?
By the way, mixing clay litter with the grass litter is useless. The clay clumping litter is so heavy compared to the Smartcat it simply drops straight to the bottom of the box, there is no mixing of the two at all.