I personally love them. I grow clover, alfalfa, oats, and a few other grasses in the run for them and they hunt n peck very well. They are quite relaxed birds. Just got complimented twice today about them. Haven't seen any aggression yet. They are alert but not flighty. Overall friendly birds.
As far as maturing later... I'm in no hurry. If I get in a hurry I can always order a bunch of cornish cross or freedom rangers. But I kind of like the thought of keeping this breed around. I have never eaten one of these so I don't know if it's worth the wait or not but I'll probably keep some around as pets even if I don't care for the meat.