Yes, I have listened to the entire thing. Yes, more than once.
At best, most folks dismiss it as a quirky indulgence. At worst, some consider it an absurd waste of time. Both of those are fair opinions that I would never begrudge someone for holding, but as a Neil devotee, I think Arc is worth listening to and contemplating. At least a little.
I don't know jack shit about "noise rock," or whatever the fuck it is that some people consider this album. But it does seem like an earnest attempt on Neil's part to explore some of his avant-garde interests in general, and his obsession with guitar feedback, "bad" aesthetics and purposeful sloppiness in specific. The album can be experienced as an expression of the philosophy of Crazy Horse, distilled to its most basic elements.
I'm sure by my description it sounds intolerable, but it's surprisingly listenable and even, dare I say, well produced. It's been edited in such a way that it frequently builds, climaxes, and builds again, almost like "real" music. Take that for what it's worth. It's not entertaining or pleasing in the way normal music is, but it is at least defensible as a work of art.
Rating: N/A. It just doesn't seem right to compare Arc to his other works. You might as well compare one of his albums to a painting or a sculpture. Either that, or consider the "N/A" rating a simultaneous "A +" and "F -."