Clumps well, but can get very dusty
I have this in 2 litter boxes (one semi-covered, one open air) and the one slightly covered turns in to a dusty desert. It still clumps and deodorises well, but can leave yellow paw tracks around the room.
The open air one is fine, stays solid, clumps well, stops smells (as long as my cats actually cover it).
It's as good as clay, but I prefer my cats to lick corn dust rather than clay dust off their paws.