I bought my Sienna right after the birth of my first child.  I had a small two door car and wanted something that would be more convenient to get kids in and out of and have room to store their gear (I couldn't even fit the travel system stroller in my old car's trunk)

We test drove several minivans and decided on the Sienna.  I has a lot of room (made a trip from Florida to Chicago and Christmas with 4 adults and an infant (plus luggage, baby gear and presents) in total comfort. 

Would be nice if center seats stowed in the floor, although I haven't really needed to stow them.  Tha rear seat...