This slide shows the weaknesses of the current mode compared to the voltage mode. In current mode control, when proceeding from one level to another one, it will go as fast as possible to the next one. That can cause some mechanical vibrations, particularly at low speed. At the same time the average current is lower than the target current as a decay is performed as soon as the current is equal to the target current. Therefore the positioning is less accurate and there are some torque ripples. And as the switching frequency is not constant, it is noisy at low speed.