A complete failure
I thought I'd give this one a try too, but I definitely won't be buying it again. It covers up smells well, but:
1. It makes a lot of dust, so the cats' fur, their paws, and the floor are always dirty.
2. It's very fine, and the cats drag loads of granules out of the litter box. I even have a mat in front of the box, but it doesn't help much.
3. The clumps are really brittle, so it's impossible to scoop up all the leftovers from the litter. Even if you leave the clumps for a few hours to harden, they still break apart when you try to pick them up with the scoop.