Learning: Older Child, Britax

Seeking Britax Advice

I am currently in the process of buying a new carseat for my almost 3 year old. She has the Britax Roundabout and we are ready to move our 9 month old into that and promote her. I am trying to figure out what the next carseat should be. Marathon? Regent? I think the Marathon should be fine as it goes up to 65lbs and I have thin little ones. I imagine they would be at least 5 or 6 before they hit that weight. At that point, I imagine we'll move them into boosters. As for the REgent, I know that goes up to 80 lbs but I do know that my...