Does anyone have these? My 9 yr old is outgrowing his HB Turbo (and his 7 yo brother isn't far behind ) and I was wondering how much growth room he would have in a PW. His torso height is 19.5 inches. He's right at the top adjustment now, so when he grows, we have to put it away. I'm wondering if it would be worth it to buy a (or two) PW(s), but at this point, I don't know if I should just suck it up and use the TB's backless. I don't wanna. Opinions? Anyone have the PW belt guide measurements (adusted as high as it will go) Thanks!