I have the ergobaby 360 with the infant insert. I tried my baby in it yesterday - he is 1 week 3 days old and at birth he weighed 7.3lb (not sure about his current weight!) he is quite a slim baby however, he has the least chubby baby knees I've ever seen. Anyway, he seemed too small for it even though they say its good from birth and 7lbs up. He seemed squished up and wedged inside and his little face was really low down and basically peeking out the arm hole.
I freaked out that he wasn't in a good position for breathing and decided not to use it and took him out in the pram instead. Has anyone else found this with this carrier and smaller babies?