How fast is the electric thruster?

Could you please elaborate on the speed capabilities of the electric thruster? Are we talking about instantaneous acceleration, maximum sustainable velocity, or a specific range of speeds it can achieve? Additionally, how does the electric thruster's speed compare to other propulsion systems commonly used in space exploration, such as chemical thrusters or ion engines? Understanding the specific context and metrics for assessing speed would greatly assist in providing an accurate and informative answer.