Here are some pictures of my closed loop stepper with Keling KL23H2100-35-4B steppers with USdigital differential encoders mounted and using my Cobra_SV closed loop stepper drives. After using size 23 DC servo's on some of my table top machines, i found the small DC sero's didn't have enough torque and were overloaded easily. (size 34 DC servos are still a good choice for a larger machine though)
The closed loop stepper is a far better choice for a direct leadscrew connection with its much higher low speed torque. And also after a few years in service all stepper machines can start to loose steps because of dirt in linear bearings etc. The closed loop stops the machine and saves your work, if it detects you have lost steps.