S.P.
My 6 yr old daughter was in a 5-point harness up until just a few months ago. She has always been petite so I thought why move it if we don't have to...it never bothered her, until the straps started getting a little tight. ;-) I noticed this past school year that a lot of the kids had the backless boosters and I've considered getting one for field trips since they are so easy to move in & out but I must confess that I am neverous to actually use one. So for now, she is still in her big Graco car seat using the seat belt...which she thinks is "so grown up".