With any food changes there should be a mixing of the two kinds to lessen any digestive troubles. I think you will have fun with them, they are entertaining.
I personally raise my poults on a non medicated chick starter. I've raised several batches on it. They grow fine and I can't see there's a difference in the end. I do know that a higher protein feed is recommended during the first 4 weeks than you are supposed to lower the protein down. I...