Hope all works out for your kitty whatever you pick. If your cat free feeds Innova dry please watch out for weight gain. Science Diet can do this too, but of course, there is no comparison nutritionally between the two. Innova is a great food but I have seen cats get fat on it, including a former cat of my own, and not all cats do well on it in terms of digestion, as we can see in this thread. But those who do well on it do VERY well, so Innova fans don't beat me up. I'm sure your cats are doing great or you wouldn't keep feeding it. It's just that I've fed so many cats in my life I generally steer people toward foods that have the least incidence of digestive problems. However, I know nothing of the California Natural, so going with Innova may really be the choice. Cats like to eat a "mouseful" at a time, so free feeding of dry is often helpful so they can eat several "mousefuls" throughout the day, so you will have to control how much she/he gets. Please include both dry and some canned in your cat's diet. Cats aren't great drinkers so the canned food helps. Good luck to you.