I have had this litter box for about a month and have noticed a couple of things about it.  
1. It is easy to clean (if needed, depending on your cats) and easy to find the supplies for it.  
2. The crystal litter has a little bit of a goofy smell to me, but until this I had always used a different brand a clumping litter
3. It's nice that it doesn't produce "dust" like traditional litters do.  This would be  a good thing for people that have allergies or are sensitive to such things.
4. My cats are willing to use it occasionally as long as it doesn't move while they are around it.  If it does it's scooping/grating thing while they are near it, they come around it for a few days again.  
5. I personally wish it had a lid as my cats have horrible "aim".  Even in more traditional litter boxes, they always use the sides of the box.