Where can I see Hokusai's Great Wave today?

What's the advantage of seeing an original piece of art over a serviceable replica? Especially in the case where the "original" is a print, one of dozens.

Obviously "serviceable" is doing a lot of heavy lifting here, a replica might simply not be very good, might not capture some vital characteristic of the thing which makes it a great work.

But otherwise, it's basically that the knowledge of how important and significant this work is puts the viewer in a more receptive frame of mind, right?

To be clear, that's not nothing. I of course know firsthand how much that affects the impact of a painting, museums and galleries care a lot about how they display their collection. But is that it?

As you say, some works seem to lose something in any reproduction. La Giaconda (Mona Lisa) is a great example: any reproduction you may have seen in books or online hasn't captured the rainbow of background color in the original, or the sensation of viewing a living person sitting for a portrait when viewed at a few paces in the Louvre.