Sleep Problems: Britax

Britax Car Seat? Car Seat for Air Travel?

Hi ladies, we are in the process of looking for a new car seat for one of our cars. I read a request and lots of responses a couple days ago about reviews of convertible car seats and found lots of helpful information. Now that I'm looking into it more I have more questions though. I'm leaning towards a Britax because of their great reviews and safety ratings, but am not sure which model. Any of you have experiences with the Marathon, Decatholon, or Boulevard? Another thing that I'm thinking about is the fact that we will be flying to...