I had two Barred Rock hens a few years ago from a 4-H "Hatch Off" at the fair. Both hens were extremely sweet, friendly, in your lap chickens. They had no problem putting the cats or any foster puppies I had in CHECK.
I now have one 12 week old Barred Rock named Joon who is wonderful. I had another Barred Rock when I got them as day olds and picked the friendliest. Neither were mean though, one was just shyer then the other. I can hold my hand to the front of Joon's legs and she will step to my hand and perch, exploring the world from the new fun height. Anytime I have a bucket of ANYTHING she comes running. She does not pick on her EE sister (who is submissive/shy) but she does 'put her in her place'. Never blood or any worries though. Joon is a total comical personality, and she was the first to Bok Bok instead of Cheeping (Which my EE still does at 12 weeks).
My experience with Barred Rocks has been nothing short of great. I will never have a flock without them. They are awesome layers, even through the dead of winter, personality galore, cold and heat hardy, and the one's I have had were totally friendly with all the kids in my family. We had a 2 year old at the time too.
I am sure personality can vary, especially in hatchery birds, but I rarely hear of bad experiences regarding Barred Rocks. Joon was from Belt Hatchery.