In a discussion about motors with a friend who used to work in the robotics industry, he told me that he despised stepper motor systems, as every stepper based system he had worked on required a bunch of hacky software fixes to make the system perform to the required level.
He said that servo motor based systems had their own foibles, but at least they could generally be tuned out and you always knew that if the encoder said you were in a given place then you would be (to within the constraints of the backlash compensation).
Because of this, I was wondering if there were any options for using brushless DC motors + encoders + drive electronics instead of steppers + drive electronics.
I think using these technologies is possible, and may be better than stepper motors, but by using these you loose the main advantages of the steppers : the simplicity and the cost.
When you use steppers, you assume your motors are strong enough to don't loose any step, and you "just" command them. Steppers are not so expensive and are compacts, so your 3D printer is "simple".
If you use separated motors and encoders, you can do better job, but your 3D printer will be a lot more expensive, harder to tune, and harder to program.