on some things I agree with @joeaverage, on others I don't.
I also had the impression that cslab has always shown little interest in Mach4, (my personal opinion) also because of the limited diffusion of the program.
on Hicon Integra I can't rate it because I never owned it.
on the SSE that I have on the pantograph, I tried Mach4.
on this point I have to score in favor of the cslab, compared to the SSE I find it clearly superior.
if with ESS you work on the progress slide while you work, it often gives bad shots to the axes, which with cslab does not happen at all.