Restrooms. I'll take the Japan Rail model over whatever fantasy version of Amtrak is on offer. I took a five hour, end-to-end trip in Hokkaido this summer. No amenities whatsoever, at least as folks on this board seem to define them. Not even a snack cart. But the train was spotless, staff were impeccably polite and efficient (even by Japanese standards) and it ran on schedule, to the minute. Bikes are allowed on board, without restriction and with no special space or equipment for them (but with the requirement that they be covered, in the interests of cleanliness). That was story on every train I took, except the Shinkansen, which did have a snack cart. It's what you get when trains are run as a mainstream transportation service instead of an amusement park ride.