I run toothed belt on both my mills, the bigger one has a heavy table and servo drives, if the belt is tightened just right there is no backlash to compensate for at all. The belt can move slightly but when that movement is converted to rotation and then reduced by the screw pitch, the actual distance linear is microscopic.

I have tried backlash comp and i would not recommend it to anyone - always get the system mechanically sound and unless you are working to nuclear industry standards, just learn to live with the tiny backlash we have - there will ALWAYS be backlash or the system would not move, its just a matter of knowing how much.