I've heard about BHA and BHT not being good for cats, but have never heard of the antioxidant ethoxyquin. (I'm a chemist.) Science Diet has a new formula that is preserved with vitamin E and citrate, "natural" antioxidants. I'm not sure how good, bad or indifferent it is; bottom line: my cats love it, they have good coats and...um...deposits, and seem healthy enough.

Food is one of those issues where you'll get n+1 opinions from n people.