LO is a week shy of 3 months. She's probably 13 1/2 to 14 lbs and about 24.5 - 25 inches long. I have the ergo with the infant insert. The instructions say you must use the insert if under 12 lbs and/or under 4 months. I tried to put her in the insert but she hated it and it felt wrong. I think she's way too long for it and she doesn't like her legs all bent up to her chest. Also her head was totally out, so it wasn't offering support anyway. Then I tried to put her in without it but I don't think she's ready to have her legs splayed out yet. Does this mean we just have to wait to use it until she's ready to sit comfortably in it without the infant insert? Has anyone tried using the little butt pillow that comes with the infant insert, but without the infant insert? I tried, but at that point she was annoyed so I couldn't tell if that might work so that her legs don't have to be spread so wide.

She loves being in the K'tan but I was ready to try the Ergo since she's getting heavier, hoping for a little more support when we're out for a longer time!