[juchong]

I think you're assuming that the PID values control only the motor output. In reality, these values are used to control an entire system. One person's kitbot transmission may be different from someone else's which would mean that their values will be different. You have to sit down and tune your robot to how you think it responds better.

The P, I and D will all cause the robot to behave differently. I can recommend as a general rule of thumb to try a value < 1 for I and something around 20~30 for P (I'm not exactly sure on this value). Leave the D at 0 until you tune these.

You should definitely read the document mentioned above in order to understand what each value does to the system. Only then will you be able to see what it does and how it reacts.