I had been contemplating purchasing a self-cleaning litter box for quite some time now. However, I recently downsized and had no good place to put the litter box in my new home.  I finally made the purchase, and I bought the ScoopFree Self-Cleaning litter box.  I love not having to scoop every day, and there is essentially no smell.  The only thing that I am disappointed with is that I thought there would be no more litter outside the box.  The kitty’s (I have 2) still track the crystals on the floor, but it is not nearly as bad as the mess regular litter made.