She's on Diamond right now, appears healthy and happy, but I want to be sure she gets the best. If you ever want to start a long debate amongst dog people, just ask a group of them which kind of dog food is the best. This question will never go away. There is NO best kind of dog food, plain and simple. If your dog is healthy, has a nice coat, is active, doesn't shed excessively or show signs of allergies, thank your lucky stars, continue to feed that food, and keep your hands to yourself.
Some dogs do great on one brand, some dogs do terrible on it.
Some are too expensive, some are just too cheap. Some are too hard to find, some are readily available. If it ain't broke, don't fix it. Don't let anyone tell you that Brand X sucks sheep doo-doo and Brand Y is delivered to their front doorstep by angels. They may like it but that doesn't mean you will.