Yes to what zeo and jools said. it really depends on your childand your vehicle, so trying the seats for yourself is best.
I have done measurements, but honestly, found those to be less reliable than the pics of how much room is left...as you can see, she has abotu the same in the aoe and frontier, and a lot morein the nauti.
However, going by straight number,the nauti and frontier are almost the same height, and the aoe is a good inch lower.
I think the main reason the aoe and frontier give the same room in use is that the recline block on the frontier really eats up the harness height, whereas the aoe installs really upright and "gains" you harness height. I've found almost a half inch difference in the nauti installed in teh same position with versus without recline. *shrug*
And then you add in the gravitationla pull of the moon and butterflies flapping their wings in Asia and it gets really complicated......LOL.....