My 9 year old is still riding harnessed in a Diono Radian RXT. My 7, 6, and 4 year olds also ride in the same seat. When I mentioned it to others they seemed shocked that my oldest was still harnessed. He's small for his age so he still fits within the parameters. He suffered a severe head injury at the age of 5. So I tend to sway on the cautious side. Please tell me I'm not the only paranoid mom!