Hi there Blossom. There isn't an easy answer to this one, and you will likely not got a straight answer. The best food for your dog is the one she eats, looks good on, and is middle up cost wise (spend what you can afford to get the best quality). I'm afraid I have fed neither of these foods, so can't comment specifically.
Royal Canin is excellent and all our Guide Dog pups are on it. But it's very expensive. I feed Tatze on Skinners salmon and rice and she is just as fit, happy and healthy as the pups - and it costs exactly half the RC food. If you look at the ingredients they are better! .