✔️ WHY I LIKE IT: Mockingbird's stroller starts as a single stroller, can become a double (or even a triple), then goes back to being a single when you need it to. But you do need to buy the add-ons—such as a second seat, bassinet, car seat adaptor, or a ride-on board—separately. The basket is deep and holds up to 25 pounds of cargo, so this is useful for parents who find themselves hauling a lot of stuff around. And one said, "The stroller is great for families looking for a flexible, long-term stroller system." Our Lab expert who used this at home, Stefani Sassos, Nutrition & Fitness Lab Director and a mom of two, agrees.