The machine X&Y is within .0003" mechanically. The Z axis is boxed with a counter weight and is within .0005".
Having feedback from actual slides and not just encoder on servo, will make up for the small amount of mechanical friction/stiction issues. First done this on a bridgeport clone that had steppers ,several years ago. Closing the loop at the table made a big difference for that dovetail machine. Went from machining a 1.0" hole with about .0015" hole roundness to .0005-.0007 roundness, sometimes better, very consistently.
Also i have a old Magnaturn South Bend Lathe that i am retrofitting now, little at a time and would like to find a good linear scale for it also.And after it a Router/Plasma table. To many projects, especially now that i have my own shop that needs to make me money.
Troy