Cohen has been in this Radian 65 model since age 1 but I think we're moving him over to the Monterey Booster (pictured below)and putting Jace in this one. The Monterey's head rest raises up for full head support of taller kids and it goes up to 120 lbs. (Not that either of them will weigh 120 lbs any time before high school graduation but just in case.)
This Monterey Booster also has 2 cup holders! I wont miss having to hand Cohen a drink and then take it back 100 times each errand we run.