Ahh... Now we are getting somewhere! They are using the drive in position control mode (Open loop to the Galil). Just like a stepper motor. Although I don't know why, as the drive will do analog speed control as well. You can use the amps as they are setup. You should have 4 stepper jumpers enabled on the Galil card. But you are not running in closed loop this way. Not from the Galils PID loop's perspective anyway. The PC drives may do some form of closed loop for you though. I'm just not that familiar with them.
What I would do is disconnect pins 17 & 19, wire pins 8 - 13 to the Galil ICM's main encoder inputs, and then wire the Galil ICM's MOCMD to pin 1 and GND to pin 2. You may have to configure the drive to do speed control instead of position control with the drive's configuration software. You'll get much higher speeds out of your motors that way. 12Mhz counts. vs 3Mhz. counts. Less time cutting air. And you'll get a true servo loop out of it. You could do this with Mach or CamSoft. It makes no difference, as the software is only controlling the Galil. (Unless CamSoft limits the speed)
But those drives, motors, and the Galil should work fine with Mach. Now I've done this a time or two, but I could have Mach driving that machine with speed control in less than an hour.
Were you having problems with CamSoft? I ask because if you were happy with it, the easiest thing to do would be to keep it.
But if you want to give Mach a try, I think you'll ultimately get better performance out of the machine and possibly gain some flexibility if you were looking for any. You can design your own interface screens, write macros that do specific things that are tailored to your production, etc... Even add a tool changer if it doesn't have one. And you have all of the PlugIns too. Joystick control. MPGs... The list goes on. Mach just gives you more options. That's the main reason I think Mach is better. If you decide to try Mach out, make sure you download the Galil's programs with SmartTerm and back them up in case CamSoft put something special in there.
Steve