In terms of hardware i am firmly in the "if it aint broke, dont fix it" camp.

Can it be improved with the newest servo spindle and stepper motors and fancy motor drivers?... most likely but as they all currently work i doubt there is much of a difference to be had other than speed and as its not for a comercial environment i can wait a bit longer for a program to run.

The motion controller however is one area where an improvement could show great benefits as thats the interface between the machine and software.

My current thinking is the CAM software is most important and that will likely determine the direction i head with the motion controller

I need to sort out my Fusion360 as its gone a bit funny with the licence but i can then have a look at the inbuilt CAM post processors and go from there.

Sorry i am a rambling mess of many directions... no final direction yet lol