Typically, a servo motor has 30%-60% higher torque capacity and 30% better torque utilization with faster acceleration and deceleration, compared to asynchronous (induction) type motors. But is this really true?

The reason I ask this is that I just bought a 600W servo motor, which I will use in my DIY lathe as spindle motor, and I also consider buying a drill press which has a 500W single phase motor. This Guede GTB16/500 Vario, and the 500W motor is much larger than the 600W servo I have. I know much of that size is because of the large heat sink around the motor, but still... Could I replace the 500W motor with a 1kW servo and get a twice as powerful drilling machine which could be reversed and driven really slow? Would I get a similar, slightly more powerful machine if I'd replace the motor with a 600W AC servo?