The actual measurement doesn't seem to correspond??
I didn't have a measuring tape with me, i as going off my kids measurements.
All i know is, dd;'s torso sitting against a wall, legs crossed, is 16 inches even, maybe 16 and a quarter, and she is dead even with the second to top slot in her nauti, and yet has a good inch in the gen 65. That measn the top slot of the gen 65 is about 1 inch higher thanthe second to top slot of the nauti...which is also, since the slots are exactly 2 inches apart, approx 1 inch below the top slot.
Another poster just posted the same thing...her dd fit into the nauti about even with the second to top slots, and absolutely had an inch+ of growing room in the gen 65.
When you measure it though...it doesn't seem to make sense. That poster got 15.5 for the gen65, and 17.5 for the nauti, which would seem to indicate a 2 inch difference in top slot height...but yet, based on how her child fit, the difference was only an inch or so. so...?????...ya? another phantom seat?
All i know is, my dd is well over the top slots of say..the titan, which has 15.5 top slots, and the AOE, which also has about 15.5 top usable slots....but yet still has room in a generations. so regardless of teh measurements, I feel confident telling a parent whose child is outgrowing one of the smaller, shorter-slotted convertibles like a scenera, titan, tribute, comfortsport, 40-lb AOE, etc, that they will in fact gain harnessing time in a gen65. Not as much time as a nauti, but probably *enough* time for most kids to get to a proper booster age.