They are sometimes hard to assemble. Pieces don't always snap easily, but that is not always a bad thing. The strollers are sturdy. I have purchased 3, and have never had a problem with anything falling off, or having any of them cause me safety concerns. Design The only thing that I didn't like about the design was that the bottom basket can fold down when you put items into it. Durability Some of the materials tend to fade over time.