When I first got my cat, I didn't realize that his life's goal was to dig to China in one litter box visit (he can't quite seem to get beyond the bottom, but A+ for effort). This pan has saved me a ton of cleaning (we originally had just a regular litter box... one with normal height sides... that was short-lived). I would recommend this product to anyone who's contemplating getting a cat.

Pros: contains litter when cat decides to dig

Cons: can't think of any

We use these litter boxes for cats with small kittens or very young motherless litters of kittens at the shelter.
The low entry opening makes it easier for small kittens to use the enclosed pan. An enclosed pan helps us keep the cage cleaner and the play and dining area of the kittens cleaner. It also creates a second level on top of the box for kittens to play or for momma cat to have some time away from the kittens while they are still small.
If the top and bottom were joined together more securely it would be better.
the large opening also gives momma cat plenty of room to move.

Pros: Low entry opening and large door size

Cons: Top does not attach to bottom securely

My cats liked the enclosed pan. It did keep the litter in for the diggers. My male would spray the back, though, so I was taking it apart to clean it a lot.

Pros: Private for the cats

Cons: A little work to clean for sprayers

I thought this would help keep the litter contained, but my cat was scared of the hood and would not go in this box. I went back to the open litter pan.

Pros: Keeps litter in

Cons: Cat scared of hood