I have a side-by-side and I HATE it. The kids can easily reach one another to take things, hit, bite, pull hair, and just generally annoy one another (this might not be as bad if one child is older, but mine are twins). It also gets stuck a lot when we go through doorways - you have to make sure the wheels are lined up perfectly straight before trying to get through. I know tandems have issues too - heavy, won't fit in some vehicles, kids fighting over front seat, etc. I think there are some tandems that have stadium seating to make the child in back higher, and I would think that would be nice. there are also some (Kolcraft Contours) that allow you to have the kids facing one another, or the sit & stand might be nice if your older child is getting close to the age he/she will want to be walking some.
at 2:11 PM on Feb. 2, 2010