Minimum steps per millimeter for the Z axis

In the z axis (up and down), is it necessary to use a 200 steps/rev motor? If you use a 48 step/rev motor, 1/16 microstep, pitch 2, and 20 teeth, you would get 19.2 steps per millimeter. 1/ans shows that two steps will get you a 0.1 mm layer height, which is really as detailed as I would want to go. If I make it a 1/8 microstep, I would get that each step is about 0.1 mm layer height. Is there any reason why 48 steps/mm steppers are not used for the z axis?

You can't always rely on microsteps. They are often less accurate which would lead to layer problems.
One full step per 0.1mm would be good enough for me, but since 1.8° steppers are so cheap and commonly available, I see no reason to change the steppers on z axis.
-Olaf

To be honest, this is a scrap build (I am really only buying the extruder and electronics). With the 1/8 microstep, its good enough. My only concern is skipping steps (like you said). If I were to increase the current slightly (still keeping it safe for the motor), would it increase my chances of having a more successful microstep?