So, there are two competing schools of thought on the matter. 1.) limit the driver’s motion in case of a flip in order to limit the damage. 2.) Allow the driver a freer and fuller range of motion so that they have a better view of their periphery so that they can avoid crashes.
My feeling is that most accident from kids in that age range are caused by being unaware of what is happening around them because of all of these devices that constrain their range of motion and view. So, I like the smaller neck collars.