Depends on if you want to use Mach4 or not.In particular I am trying to decide between the motion control board and am wondering if I should use an ESS or a UTCC400.
The UC400 works with both Mach3 and UCCNC, with UCCNC providing better motion.
It will not work with Mach4.
The ESS will work with Mach3 or Mach4.
Personally, I'd go with the UC400 and UCCNC.