Absolute encoders are for absolute quality
Absolute position system gives incredible results. You can restore the 3D printing at any time even after the power fail.
More than 1M positions per resolution resultes in higher than 0.000005mm theoretical resolution. Just imagine it is a thousand times less than the size of an average cell. It is still amazing even though we do not use the resolution over 1um for objective reasons.
C5 grade ballscrews are within the standard version.
C3 grade is available on demand.
For the best absolute results, selected printers can be equipped with the optical scales.