the cc bec is so you can run higher voltage and have more available amperage for your electronics . all a cap really does is flatten out voltage peaks and it does store some energy so if there is a drop from the esc it can help to keep the amperage up . i use the cc bec for crawlers running 3s and even 2s so you can run the radio gear off the main pack and the voltage is constant whereas a esc can fluctuate and overheat the internal bec,especially with good high torque servos