Hi John,
In my mind Mach3 / Mach4 is nothing more than software over "metal"
Currently its based on a parallel interface ( EPP Mode - 2MB/s ) which is poor by today's standard, even on the widely spread USB2 ( 35MB/s ) which is now considered a standard since everything is being further pushed towards USB3.0 ( 500MB/s).
In my head... a USB interface is easier to use then the bulky DB25 and also makes it easier to deploy almost any cheap laptop on the market.
The EPP ( Enhanced Parallel Port ) is the main drawback and with the prices of other "mach" specific hardware isn't so DIY friendly.
( By the means of "mach" specific hardware I'm referring to Smooth Stepper which are still sitting at around the $200 for even the counterfit ones on eBay, where as the Due and the shield is around $80 )
And as far as support goes its pretty rock solid as plenty of people are using it for 3D printing, which is similar process (instead of removing material your adding it)
The firmware is already in place for the Arduino Due and the RAMPS-FD shield to either run from the SD card on the LCD shield or the PC by the means of USB.
The software would have the same abilities on any similar hardware, and the only difference would be the response.
I would think that there might be a slight delay, BUT It's highly theoretical and doubt it as the the data path from the controller to the PC is 17.5X faster on USB2.0 VS EPP.
This way for those that would want to turn their mills to a 3D printer it would mean nothing more than to switch "plugins" in Mach 4 and swap out the router for an extruder.
I cant say the same for many of the 3D printers as not all of them would fair well if they were changed into mills as I first hand saw a few "woodie" builds over on the Reprap forums.
What im asking is if anyone has tried to use 3D printing hardware with Mach3 and what was the outcome.