My biggest complaint is the mounting screws on the motors. You need a box wrench to tighten them, and it is really easy to strip those holes. What was wrong with the #8 screws they used on everything else in the kit?
Also, the chain is pretty lousy. The chain that came with my Lego Technics kit was thicker and stronger.
Still, the
miniFIRST teams here at WPI have been able to cook up some pretty cool stuff.