I have installed an RXT RF with no AA in my Honda Fit for my nearly 15 month old and he has terrible head slump when he sleeps. No slump at all in the CCO. The RXT is as reclined as I can make it in the Fit and he is still flopping all over the place. Is this something that is likely to improve with age, or should I move the RXT to my husband's car (which he barely rides in) and get a MR or S4M instead? He has a ginormous torso, so a tall seat is essential.