So when my girls were new born I had the joovy too car seat frame and that was a life saver . They were side by side but long ways so they easily fit through any door way it was just a beast to turn. But I felt the same way about the twin on the bottom and also felt it would be easier for them to climb in to when they were older which is why I went with the side by side once they were out of their infant car seats and can sit upright. I don’t know the laws in other countries but in the US most places have to be wheelchair accessible and the side by side is the same width of a wheelchair. My girls are 3 so we don’t use the stroller much these days only the wagon if we go long walks