While there is a limit to the gear that can fit inside a bag this size (as it fits squarely onto the back of a 2 year old), it should be remembered that the stuff a 2 year old needs to carry round with them is also similarly scaled down. My neice is thrilled as her gloves/sweater/juice are now her responsibility, and I'm thrilled (because they're now her responsibility).
What makes these packs exceptional is the build quality. I have seen adult, military issue kit that is not stitched together as well or as securely as this toddler pack. It is that strong that not only can the toddler carry everything they want to carry in the pack, but that the toddler can be carried by the pack without their feet touching the floor when you're in a bit of a rush. Together with the equally strong leash, this means that the toddler can now accompany you on adventures that previously were beyond their capability.
If I have a complaint, it's that the equally well made rainhood (which is great when it showers, as it can just be put up) has cartoon eyes painted on it. This is a very adult complaint about it being uber-cute, my neice thinks the eyes are the best thing since sliced bread and tends to have the hood up all the time.