Pros:

• Design robot is very interesting and open-source. With a robot design that can be customized well, not only children who will be interested to explore, even adults will also like this product. Its open-source nature provides added value because players will create the shape that is in their brain.
• Robot can move. Although the movement may be very limited (just walking), at least they can move and this is very fun.
• Integration with Smartphones. This innovation is really very interesting, because we can integrate the control of robot movement with Smartphone.
• Voice recognition support. It is very rare that child toy hardware technology has this kind of technology. It's sophisticated and fun to use as a means of exploration.

Cons:
So far no one, except maybe from the price that must spend too deep.

I see on the site "Mi Robot Builder" that you specify not listed price. Suggestion: maybe you should include it, so we can think about whether this product is worth buying or not.