Marathon or Roundabout (or both?)
12-month-old DD is about to graduate from the Snugride. We currently live in NYC, and do not own a car. For the next 6 months, until DD is 18 months, we'll remain in NYC, and after that we're planning on moving to CA. We'll only use the carseat for travel and cab rides until we move (a decent amount of both).
Once we move when DD is 18 months, we'll be getting two cars, and we'll need two carseats.
I'm wondering whether it doesn't make sense to get a Roundabout now, and then buy a Marathon for our second car when we move in 6 months. It seems like it would be nicer to have the smaller size of the Roundabout for travel and cabs over the next 6 months, and even continuing for travel once we're back in CA. And it seems like, once we have a second child, we'll eventually be able to use the Marathon for DD and the Roundabout for the second child (after he/she outgrows Snugride). A third child is possible, so it seems like the passing down could continue.
Anyway, I guess my main question is whether I should just always buy Marathons because of the higher height/weight limits (as that is the most economical), or whether it might make sense, if you're going to buy two Marathons, to instead buy a Roundabout and a Marathon so that you have the flexibility to travel w/the Roundabout and because you can kind of pass it down the line to future children for a few years anyway.
I'm wondering as well whether either is easier/harder to install with a seatbelt, as that could affect our decision. In cabs and for travel, we have to do a lot of seatbelt installs. Also not sure whether anyone knows how either/both fit in cabs, generally.
Thanks very much in advance!!