Are you looking at the same brand (Cozy 'n' Fresh)?
I have noticed that this litter has a little bit of a different smell than the Feline Pine. I don't know if the carbon could cause problems if it were ingested. My litter box has a built-in grate so my bunnies never come into contact with the litter. It also restricts the smell a bit, so I can't really tell if the carbon helps with odor control. Oh, and it seems to fluff up more when it's wet than the Feline Pine litter does.