So far, we're liking our "sit and stand" stroller. There are just so many permutations: Aaron in the front and Jada in the back, Aaron in the front and Jada walking alongside, Aaron in the sling and Jada in the front, and so on and so on.
Aaron seems to like being able to see out, as opposed to those double strollers where the infant seat is literally underneath the toddler seat. Jada likes having her standing space, like she's riding a subway car and has to balance herself while holding on to the handle with one hand and her water, her dolly, and four bunches of flowers with her other hand. Jada also likes poking her head under the canopy, and either rubbing Aaron's head or holding it so it doesn't flop all over the place.
Of course, when #3 arrives, we'll have to invent some new permutations. Somehow, I think we'll figure out how to make it work.