I had a booster seat with a harness which attached to the anchor point for Matilda & have just bought a maxi rider due to the fact that she is an escape artist and can get out of the harness. Its a H-harness and antisubmarining booster seat but she is 3 and 17kg and able to climb in & out of the harness. I just don't feel like its safe enough. We bought the maxi rider and will have Jovie go into that when she is outgrowing the car seat she is in & by then Matilda will be 6 and we will put her in the booster seat... thats out plan. Jovie is still rear facing & will be for a long time.