I only have one RIR, but she does seem to be a little more shy than the rest. I have a little outdoor place set up for them and I put them out there during the day, the put them back in the brooder during the night. Anyway, I walk out there and just sit and watch them. Both my EE and white leghorn love to jump out and roost on my head/shoulder, but not my RIR. She is just really shy. Although (if she even remembers) it might have some thing to do with the fact that when she was about 3 weeks, the brooder door got closed on top of her and maybe now she is just really cautious around people. That could have happened so many different times though, I'll be shutting the door and she will jump right under it (though I'm really cautious and make sure that they don't get hurt that way again).
I know what you mean about the golden sex-link. I have one, and she is the sweetest thing! She loves to follow me around, and will even climb on my lap if I'm sitting down. The funny thing is, that she didn't used to be like that at all. When she was a chick, I had one other chick that lived with her. When they were both around 20-22 weeks, my sisters dog got the other chicken and she was the only chicken I had (I still had some ducks, and even though she got along with them just fine, she still felt kind of lonely cause they were raised together and the duck were adults when they were introduced). After that, she has gotten way used to me. It's kind of funny, my cats don't like her at all (because she tends to like to go over to them and dig at their legs). I'll be holding one of the cats and she wil come over and just start nipping at my pants. The cat will sit there and look at me like "Get it away from me!!!" Although the cats love to sit and watch my chicks run around but don't like my ducklings because they will nip at ANYTHING.