About ten years ago, Amada America built the FO in the United States. Those machines were a bear to work on. It took three weeks it install one where it should have taken three days. Amada only built a few dozen during that run.
Amada has built a production facility here dedicated to building lasers for the north American market. From what I have heard, it's set up like Honda, Toyota, or Nissan. Americans doing the work with Japanese over site.
I currently maintain at least two FOM2 that came out of that factory. There is absolutely nothing abnormal about these machines. They run well.
In my opinion, I would consider who is going to service the machine. Who will set it up. If it's someone familiar with the American version, I recommend going that route.
Amada has designed a damn good machine. That's what really counts. With the proper environment and supervision, who builds it doesn't matter much.