Pellets. Much less waste.
I don't use Purina products, nor do I provide layer feed. My flock gets Nutrena All Flock pellets and I keep crushed oyster shell in a separate container, free choice. The layers take it if they need it.
My flock has birds of all ages, and I don't want the youngsters to get too much calcium before they need it. Plus, I have ducks and geese in the flock, so All Flock is perfect for 'em.