We're going to put DS in the seat later tonight and decide if we need to move the straps or not... Just curious - how big was your LO when you needed to move from the lowest slot to the middle?
I haven't moved ours yet. DS is about 25" now but when I tried the straps at the next level they were still above his shoulders. The straps should be at or below shoulder level. So I think it depends on how tall your LO is. I'll probably check again soon since it's been a couple weeks to see how the straps match up, they grow so fast!
Re: Chicco Keyfit30 - when did you move straps to 2nd slot?
Yup, at or below for rear facing. At or above for front facing. Does not matter baby height, just shoulder height in relation to the straps.