is it counted as a checked bag or is it free? I'm contemplating not using one on the plane, but if I have to pay to have it checked (flying Airtran and now you pay for all bags checked) I think I'll just use it. It's not that much of a PITA to get to the terminal/on the plane and if I'm going to bring it all that way, might as well use it on the plane, not gate check it.
Re: If you check a carseat with your luggage...