We went w/ Ds 4 and dd 1. Was concerned he wouldn't fit into an umbrella stroller but he did and LOVED having it. It is a LOT of walking! And in the morning, when you're making a mad dash to a certain ride, or at the end of the day, when you're leaving the park...it is a GODSEND. Not to mention at parades....or anytime your child just wants to chill for a bit. At 4, he wasn't using a stroller at home at all, but at disney....he was thrilled.
This next trip he will be 5.5 and dd will be 2.5. We know we're bringing one for her...and I don't think he'll fit in the umbrella. My concern is if I rent...dd will probably want to sit in the rental w/ her brother....but then, at the end of the day, we won't have a stroller to take out of the parks. Waiting in those bus lines it's nice to have a place for the young ones to sit. And then it's SO much easier to stroll back to the room then carry them and your stuff. So, I'm just hoping he can somehow fit in the umbrella one and we won't need to rent. The stroller we use for dd is a collapsable one easy for the buses, but unlike a true umbrella, it has a basket underneath which is SO handy. I really love that stroller.