[markulrich]

It does respond to the in between positions very well, it's analog control.

The WiiMote has a 3-axis accelerometer, not a gyro. It's reading acceleration relative to gravity, which means it will never read 1 g on both the x and y axis. For the video, I decreased the sensitivity so it was obvious that the robot was responding directly to the wiimote, but usually I have about 30 degrees be full power (instead on 90), and on that setting it can easily go forward and turn at the same time.