In my opinion, by today's standards, Science Diet is a low-end food, right in there with other grocery level foods, Swope. If you indicate which formulation you were thinking about, I'll interpret the ingredient panel for you, proving that it's a low end food.
They came out with a holistic food, but it's still not as good as the brands I'll list below. Even Whole Dog Journal, in the current issue, which lists their accepted foods, noted that the Science Diet Holistic ingredients have changed and declined (their words) since last year's report.
I'm a part-timer for Earthborn Holistic Pet Foods, so naturally that would be my first recommendation. But, you also can't go wrong with, in no particular order: Wellness, Canidae, Merrick, Nature's Variety, Solid Gold, Blue Buffalo, and others of that genre. We're less expensive than just about all of them,though.