One thing I have noticed with the 6560 drivers is that on the one I have on a small drag engraver unless it's set for full steps the results are all over the place.
Full steps for me on this machine are fine as it's so low geared but in micro-step mode you cannot reply on repeatability on distance travelled. Overall I'm happy and the drivers are suitable for this wimpy machine but would not buy another board unless it was for an equally wimpy machine.