zwieblum:
Well, configuring GRBL to play nice with your machine is your job to do. If you configure it to be slow, then it will be slow. If you configure it to work at optimal speed with your CNC, then it will be fast. Nobody to blame here but the user
Don't know which genius you payed to write the code (and which code that would be, as you need a PC program and an arduino program), but you get what you pay for. As you do not want to use proven working code you will most likely end up haveing spent way more than the 200+350 bucks for nothing.
I guess we'll have to see, another guy tried the grbl approach but the cnc was far too slow even at the maxed out setting.