Nordic: Forgot to say in the previous post when mentioned about higher-level servos requiring higher quality components. That this is also true to lower degree for cheaper servos over a Stepper system.

For instance, with motor coupling used on Stepper, you can get away with more springy coupler and it won't affect the motor in any way. Whereas a springy coupler on even a cheap servo system can cause big issues with tuning the motor. The same goes if using belts and pulleys, buy good quality belts and pulleys.

The stiffer you can make the coupling between motor and screws the better this goes right down to motor mounting. Flimsy motor mounts etc will cause resonance which you'll have to tune out of the system. This isn't always so easy with cheap servo's so the more you can do to limit resonance the better.