W.C.
I also check the car seat. No sence in making the seats even smaller then they already are. If it were to get lost, every airline has loaner car seats when you get to your destination, or if you don't trust theirs (I wouldn't) then you can rent them with your car which works fine if you are staying in the US. Many other countries still take the car seat as a suggestion, therefore don't replace them as they should. I have never had a problem in the US though.
The GOGO kidz travelmate looks great though. remember to check with your airline to see how many carry ons and checked baggage you are allowed. It might be worth it, not to mention the possible delays and tight transfers. If you think she would sleep in it. I would think it is worth the money. I SO wish they had this when my daughter was small enough for it.