I just bought one complete kit and it arrived very fast! the shipping took just 9 days. the customer support ist good and promt aswell. one thing to mention is that: even though the DRO has the Absolute and incremental function the linear scales do not have a Reference Mark, that means if the position changes while the DRO is off, it will never know where it was before. So, the Absolute (ABS) function is only an incremental one.
The DRO works great! The scales are easy to mount and the hardware supplied is useful.