-Production difference ? (Handmade / Machine made)
Fpgaarcade has the PCB factory made and the FPGA machine soldered. The rest of the components are hand soldered.
This was the case for the RevA boards, but RevB boards are double sided and machine made. The manufacturing is completely set up and the boards can be knocked out in high volume.
The code and schematics are/will be open source, the PCB layout is not.
The Replay board also has a daughter board connector to add USB/Ethernet/CPU and more memory.
/Mike