Rene, Natural Balance isn't by Nutro. You might be thinking of Natural Choice. You're right. Nutro isn't the best IMO. Natural Balance is a very fine, premium food made by Dick Van Patten. You can look at the ingredients. Lyric eats that...venison and brown rice formula because he has a problem with a sensative stomach and that one seems to agree with him well. I did feed Canidae, but it has so many ingredients that it seemed to bother Lyric. But I feed that to my Chi's. It's a very good food.
Another good one beside Inova, which is a super food, IMO, is Chicken Soup for the Pet Lover's Soul. They have one for pups and seniors too...lots of good, yummy stuff.
These foods are cooked at a lower temp so the nutrients aren't all destroyed and they have good supplimentation, good meat, lots of it, human grade, no corn and no harmful chemicals or anesthesized animals. They are expensive, but less waste, so really they come out about the same. My dogs' coats and teeth are very nice and they're energetic. I think in Natural Balance and even some of the other ones is some Taurine....that's good for the heart, apparently.