i chose the one behind the other stroller... as I have traveled via air/land/sea with your age children... why? 1. both will need it at the same time at least once during your trip, also if you do not have a regular double stroller, some of the sit and stands are light and compact and easier by far than the side by side to maneuver. 2. when not being used with the children, especially, when traveling at the airport from one point to another, its great for holding bags etc. 3. free check in on planes etc. much cheaper than renting them elsewhere. As a Mom, who often traveled with 2 little ones, I have found the stroller to be of great use. I will even be bringing a smaller umbrella type stroller for my 4 yr old for our January 2017 cruise, mainly for the travel to the port/cruise, even though we won't use it on the ship... 4. If you bring only one umbrella stroller, undoubtedly, your older child will want a ride too, and 2 strollers are just a pain to handle when dealing with children in airports etc.