Automatic Litterbox Central

After much evaluating, I'm on the verge of buying the SF. I have 2 cats, one seldom digs and buries, but the other like to dig around quite a bit. She 's used to digging around in feline pine pellets. How does the SF do with a digger? I get the impression the depth of litter in the tray is rather shallow.

As for the non-buryer, I'm guessing this is noit an issue, unless the #2 need to be coated in litter for optimal raking.

Thanks in advance for your comments.