I have read that some of these crosses were used in a breeding project of LF Blue Rocks in VA.I was able to hold one of the birds, a barred rock, at the Lebanon IN show, it was a solid bird, but you wouldn't think it was much larger then most other Rocks when they were in the cage. The fact that theyre using the breeder birds would probably mean that their production is better, because the breeder birds are most likely bred to be good producers of eggs, and high fertility, so that when they do the cross they can get the most bang for their buck.