I picked up a Denford (a sherline in a case) identical to the one in http://www.cnczone.com/forums/showth...d%20MicroMill?

There seem to be 2 basic approaches to modernizing the electronics:

A) Wire a BOB into the existing smartstep/3 as done here, https://www.summet.com/blog/2016/01/...-axis-control/

and

B) To wire in a new BOB and drivers.

Since it would seem much easier to replace the main board entirely, can anyone tell me why it might be better to wire thru the existing smartstep/3? If using the drivers on the smartstep board is the only reason, it seems a bit of effort for little cost savings.