We'll be traveling in December with a 4 yo (avg height but only weighs about 27 pounds, so weight isn't an issue) and a 10 month old. Debating if I want to buy a double britax agile stroller. I know I can rent, but we thought maybe it would be nice during the summer and to use on other trips so it should end up paying for itself. Question is, would a sit n stand stroller be a better option? We're not planning on going back for naps. Figured they could nap in the stroller. 4 yo doesn't normally take naps anymore and the baby is a pretty heavy sleeper right now. Does anyone have any opinions? I hate to shell out the $300+ if it isn't necessary, but I can't see the 4 yo walking the whole time.