My chickens prefer crumbles and my smallest bantams like the seramas and japanese either can't or completely refuse to eat pellets. Which is fine cause crumbles is all I can get at nearby stores. Pellets though will have less waste and cost you less in the end than crumbles.
Mine prefer crumbles. If I had made the switch to pellets when they first switched to layer feed, I think they would have taken to them better. I waited until they had been laying for about 6 months, then didn't realize that they weren't eating much of the pellets. I thought the feed was lasting longer because they weren't wasting as much.
They free ranged daily, so got much of what they needed from the yard. Then I built them a pen, and the pellets still didn't seem to be getting eaten. Egg production dropped to nearly zero. I switched them back to crumbles, and, I'll be darned if egg production didn't go back to normal in about 3 weeks.
That was in the summer. No one had been molting. NOW, they are molting, so egg production is down again. I will stick with crumbles. Switch to pellets early if you're going to do it.