Just a note here on what it "works" with. I have been using it as a slicer for a Flash Forge printer. I think the "works with 5 generation makerbot" is just for the direct connection of computer to printer. The stand alone slicer to .x3g works fine on other printers so far that I can see. I also think this is just their way of distancing themselves from their open source roots. It seems they are abandoning their previous and current customers by making this for 5th gen printers only.

I am pretty sure the slicer to .x3g will work fine on older Makerbots also. The printers are still in the selection list. Proftweak even works fine on 3.1.1.