Buyers must prioritize Voltage Range (V) and Continuous/Peak Current (A) to ensure the controller can handle the motor's load without overheating. Look for Back-EMF (Electromotive Force) sensing algorithms, as these are critical for 'sensorless' operation to determine rotor position. Additionally, verify the PWM (Pulse Width Modulation) Frequency, typically between 16kHz and 32kHz, to ensure quiet operation and high efficiency. For high-performance applications, ensure the controller supports FOC (Field Oriented Control) for smoother torque delivery.