R.A.
I live overseas and fly back and forth to the States and other countries with my 14 month old several times a year. If you aren't renting a car I wouldn't take them. If you are, I suggest buying carseat bags for your carseats and checking them for this reason: You now have to pay for your luggage at the ticket counter but carseats fly for free. I put my carseat in the bag that I bought from Babies R Us and there is plenty of room to stuff the bag with other stuff like a backpack or toys or whatever then I don't have to pay to check that stuff. If your luggage gets lost like one of the other moms said, you may want to make sure that the car rental place has them available as a backup. Taxis won't have them, but the resort should pick you up and you won't need a carseat for their bus.