I bought the Britax marathon because of it's good reviews and higher weight limit, but had to return it. When my baby slept (rear facing installation), her head would bob forward and there was no way to keep it back against the seat. We tried increasing the recline using towel rolls as the instructions state, but that just made the seat loose and unsafe. The improper fit may be due to our car, which is a 09 Camry, but it was definitely not comfortable for the baby. Otherwise, the installation was not difficult and it was easy to strap the baby in the seat.