This paper evaluates the transient performance of grid-forming (GFM) converters considering the high-switching-frequency characteristics of power devices. It is found that the disturbance suppression performance of the current control is compromised with higher switching frequencies, while employing the voltage feedforward control can improve it. Consequently, two issues of GFM converters during the low-voltage ride-through are presented, i.e., the current overshoot during the fault occurrence and the transient overvoltage during the fault recovery. Simulation and experimental results confirm theoretical analyses.