The ingredients in it are much better then Science Diet, too.

I haven't used Chicken Soup For The Cat Lover's Soul on my cats, but both of my dogs were on Chicken Soup For The Dog Lover's Soul for a while but it was much too rich for them (their stools were loose, and pretty stinky). Plus, I noticed they were scratching and itching a lot more.

Personally, if your cats are doing well on the food they are on now, I wouldn't switch it. But that's just me.