C.D.
It completely depends on the child! I have never needed a car seat for my daughter. It has always been easy to keep her busy and she has no problem sitting in her seat...and then my son was born :-) He would much prefer to run around. He sits comfortably in his car seat - even naps! He is used to sitting still in a car seat and it goes much smoother for everyone. Yes, it is cumbersome to carry throught the airport but for me it was sooo worth it. Good luck!