I did an experiment with young cockerels (4 months old) a couple of years ago. Same breed, same age, butchered the same day. One of them I cooked right away (soup), the other I rested for 2 days in the refrigerator, then cooked him the same way. There was absolutely no difference in the meat. Maybe there's more benefit if you're dealing with older birds, who knows... but with the young ones, resting makes no difference. I hadn't even heard of resting chicken until I came on this forum, and I grew up with homegrown chicken. I am about to get my hands on a couple of older hens (2 years old) for butchering, and I'm going to do the experiment again. Very curious to see how it turns out!