All the current saber boards use some kind of semiconductor based accelero- and/or gyrometer. More advanced boards use IMUs (inertial measurement unit), which combines accelerometer and gyroscope in one package and offers on-chip digital signal processing to offload complicated calculations like orientation, quaternion etc. from the controller. I'm not sure what commercial boards use, I mount one of the industry's best IMU (MPU6050) on my DIYino saber boards, because I simply want to use the best available hardware. Of course the hardware capability is one thing, what makes a real difference how you use the data provided from these sensors to detect gestures, trigger clashes and other FX's.