I have to say the jury's still out on it. I've "installed" it in the bottom of a coffee can and put it in the run about 3 days ago to see how the chickens like it. So far they don't seem to get that pecking at the lever will release food. I put a strawberry on the lever twice now, they eat the strawberry but don't continue once the treat is gone. I certainly haven't given up as I really like the idea, but can't say we've had success so far.
The seller says it works best for pellets, but gives sizes of hole to use in container for grains and crumbles. We're using crumbles.