They are starting to get the "broiler look" from what I've read they take a couple of weeks longer to reach processes weight than the CX. I'm thinking they have missed their mark by a WIDE margin. We will know the answer when they reach 12weeks.
One of the most notable characteristics of CX broilers IMO is the size of the chicks legs,and the width they display from day one. The welp slow broilers didn't have these characteristics at first. They are starting to show now,the legs have suddenly thickened and some are displaying some nice width. I have also noted the roosters are very aggressive. They will (try) to stand up to Big Boy,ruffling their neck feathers like a game chicken. I'm intensely interested to see how this breed turns out.