Back on track but I'll challenge it another way! The "best" food to me is free ranging. Chickens were made to have a healthy diet of wild grains, worms, insects, plant matter, leaves, and all that. Pelleted feed is a very narrow subset of that diet, heated and mashed and stored for weeks to months before use. Pelleted feed has value because it is convenient for the human and long lasting, so available without planning in winter, drought, etc. It is fine but not the healthiest food for the chicken. Non-gmo or organic or no-soy, doesn't matter. Fresh free range foods wins every time.
I'd encourage the OP to define what qualities or features make a feed "best" for them.
I'd encourage the OP to define what qualities or features make a feed "best" for them.