Ball screws

Hello group;
During some internet research I came across Kerk motion that has
lead screws with anti backlash nuts that they claim to be less
expensive and out perform real ball screws.

I am interested if anyone knows anything about these and where good
ball screw / lead screw suppliers are.

I also noticed that a lot of ball screws do not have the
standard .100" per rev lead that is the standard for the machines.
Does the controller software like mach2 compensate for this?

Thank you,
Ryan