For $600, the arm should be superior, which for the most part it is compared to other toy/hobby robot arms. One major flaw is no instructions. The arm uses 785 Winch servos, and they are STRONG along with a large gear ratio. Have not had much time to work with it yet, but did set it up with the Phidgets servo controller and all worked ok. Just takes a little time dialing it in just so you can do basic movements. Again, RobotShop needs to provide detailed instructions. You guys have great products and I know its for hobby users, but step by step instructions is a MUST. Add this and I would give another star or two.