The only flaws, mechanical actuators that "crack" stop (nothing wrong but the noise is unpleasant) and stabilizers that do not really rest on the ground (a very simple modification overcomes the problem is enormous advantage of Legos).
It is also possible to make the last drive axle by adding a differential and reproducing the same central gear, which is a cinch ...
In short, a model already very nice and easy to use, easily upgradeable, and comes with a tree trunk!
SUPER!
