PLEASE help me choose between the Britax Roundabout & Marathon

[McGucks]

These are both on sale and we are buying one tomorrow...help me choose!

Which do you have, which do you like, and why?

Also, our toddler is 17 months old and already almost 30 pounds, if that makes any difference.  He's also fairly tall (75%, but I've forgotten how many inches).

BIG thank you...I get very freaked out making decisions to buy things that a) are expensive, and b) I'll have to use for a long time.

[LynnS6]

I think the Marathon will last you longer, as it goes up to 65 lbs harnessed forward facing, while the Roundabout goes up to 50. I believe they both have the same rear-facing weight (35 lbs, which you'll probably hit in the next year.)

We bought a Roundabout for our older child (OK, he's 10 now, so it was a while ago) and a Marathon for our younger. My kids are especially long in the torso, but the Marathon lasted us longer. There's also a Marathon 70 that goes up to 70 lbs, which would keep your child harnessed until probably age 6-7.

[Friday13th]

I'm pretty sure in both the new generation and the Classics that are currently out the shell height are the same in both the Marathon and the Roundabout. Previously the Roundabout had a significantly shorter shell but the Classic Roundabout 50 (how ridiculously confusing are these names, right?) sold at Target, etc. is the same shell as the Classic Marathon, the shorter Roundabout isn't made anymore.

Either way, if your baby is 30lbs already, I'd strongly suggest the new Generation seats (BRU sells them if you want to try them in person) with the 40lbs RF limit. Again with these models the shell height is the same, the FF weight limit is different 55lbs vs. 70lbs but it would be an exceptionally short, heavy child that made it anywhere near 70lbs in a Marathon. I do believe the Marathon has a no rethread harness. Which to me isn't worth the price difference and if I were to buy one it would be the Roundabout 55 but that's up to you.

[mama2soren]

For a tall kid I'd skip both of those seats.  The shells are shorter than almost any other 40 pound RF seat on the market, which means they'll be outgrown soonest.  

Check out the True Fit, the Complete Air, the Radian, and the Triumph 65 for options that will last longest!