i have to say, though, growing up we fed science diet to our cats and dogs. we lived in a small farming community and didn't have many options. and growing up in such a small community, we could watch our pets' littermates grow up at the same time as ours. most people we knew just fed their animals the cheapest foods and leftovers. ours got science diet supplemented with eggs and some other raw/whole foods. and the difference was remarkable. my cat, levi, was twice the size and twice the gorgeous of all his littermates. no one could believe he came from the same parents. and that's just one of many examples.
knowing what i do about feed now that i am a "grownup," i wouldn't buy science diet ever again. one look at the ingredient list was all it took when i got sylvie. but, that said, it was better than the alternatives our friends chose when i was younger. or who knows, maybe their ingredients were better decades ago [like many huge companies..].