I had two Britax seats in the main car, but needed some seats for the car in the extra car which my two girls ride occasionally (about once or twice a month). I didn't want to have them out of a 5 point harness, but I didn't want to buy new carseats that they (esp. my older daughter) would grow out of quickly. I researched all the car seats and this one got good ratings in that it went up to 65 pounds for the 5 point harness. After the child grows out of the 5 point harness, you can remove the straps and use the seat as a high-backed booster. My older daughter outgrew it by weight quickly, as I knew she would, so I took out the straps and she used it as a booster while my younger daughter (about 2.5 years younger), used it with the straps. When my mom came to visit, and the school schedules changed so that we had just one girl in this car at a time, we took out one of the seats and just used the one as both a booster and a 5 point harness. One problem we had is that my husband often got confused as to how to use the seats. I caught him a couple of times strapping our younger daughter into the 5 point harness when the seat was unfastened and *should* have been used as a booster. AAAAAhHHH! Another problem was that my older daughter quickly outgrew the seat by height--it's quite a short booster compared to others out there. We finally just started using the Graco highbacked booster for her (she's nine now; I think we bought it for her two years ago) and kept this one as a booster for the younger one (she is six and quite small for her age). However, a friend just told me that a backless booster was safer than a high-backed one. I'm going to do some research on that issue right now.