Hello,
The closed loop operation is not just for Maxsine motors that we sell, we have many customers that use this option with other brands like Yaskawa, and Teco. As long as you can get encoder feedback that is 5volts differential quadrature type, you can set it up with our Integra or DSPMC controllers.
If your drive supports differential step and direction signals, that is the best way to avoid loosing steps. If the motor and driver are closing the position loop themselves, then you do not need closed loop setup. However, if you have linear scale on the table, using closed loop with the controller will give you better precision.
Using AC servo motors will give you more precision, speed and torque compared to a stepper motor/drive. eg, with Yaskawa servo drives, you can set extremely high counts per rev in the range of 50000 or even higher, which I don't think you can ever get with stepper systems.