Car Seat

Pros

• Car seat all the way. Much safer in the event of turbulence (or heaven forbid a runway accident like the one that just happened at LGA). And contains baby in a comfortable position for sleep.
• I would 100% buy a seat for kiddo and use your carseat. That will give him a place to sleep and you the ability to have free hands. Trying to hold a 13 month old for 8 hours will not be a fun time - don't do it. And of course in the even...
• Safest is to buy your baby a seat and use a car seat.
• Bring your car seat and install it, or buy one specifically for travel. It’s the safest way.
• Buy a seat and use the car seat. Safest approach for your baby. Car seats have to be approved for aviation. It will say it on the side of yours.

Cons

• I had a very bad experience from one of the larger rental companies presenting me with an unusable car seat for my 1 yr old.
• If you would truly have a stroller and a separate car seat, I wouldn’t bring a car seat. No way to handle several suitcases, a stroller with baby and a car seat. Lifting those in and out of trains seems like a hassle. And you can easily...