Panasonic builds primarily industrial welding power supplies for factories and robots. Really solid stuff, high end. I have heard good things about these mig welders.
my question would be- how propriatary are the gun parts?
gun liners, tips, wire drive rolls, that sort of thing.
With a miller or lincoln, you know you can go into any welding supply store in america, and they usually have parts, consumables, and new liners on the shelf.
I would want a third party gun on one of these- a Tweco or Bernard or something else common as dirt. Either that, or stock up big time on tips and liners and drive wheels and spare gun parts.