My Partridge Rock chicks have grown much faster than most of the other ladies, they are HUGE, and my friends (who has an identical flock from the same hatchery, Murray McMurray) grew much much smaller and got their feathers later. Hers are her smallest and scruffiest, mine are my largest.
It's strange though, they are totally uninterested in treats. They never come over and have become very shy, which is strange because both of our Partridge Rocks were usually the troublemakers in the flock as chicks, and very boisterous and active. Now they're 4.5 weeks old and they've totally mellowed out (not in a maybe they're sick way, they still look healthy). Maybe it's because the Buff Rock ladies have taken over as the flock masters.