The greenBull can range is routing width sizes of 5 feet and 6 feet. The blackFoot has a 4 foot routing width.
The greenBull machine has a sturdier gantry than the blackFoot, so you can be more agressive with the cutting feedrate (cutting speed). The blackFoot is also a good machine, but it all comes down to the speed at which you want to produce the fabrication
The spindle is also highly recommended for it's quietness and easier cleanup (no fan blowing the dust in the air)
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WHICH MACHINE SHOULD I BUY, GREENBULL OR BLACKFOOT?