Feathers definitely make a difference in how the bird looks, regardless of size. I have a 4 month old Jersey Giant cockerel. He is hilariously huge, twice the size of the other young birds. But when I pick him up he is scrawny under all those feathers. I am interested to see how he fills out over the next two months since that breed is supposed to take 6 months to maturity, but he is much thinner than the BLRW that is about the same age even though they both look huge with all those fluffy feathers.