Comparison between the Japanese, Koreans and Hong Kong Chinese:

Culture - all old and lots of beliefs and superstitions
Infrastructure - (Japan) good roads and highways but small pedestrain walk ways in some areas; there are 2 subway networks plus the JR Rails which can be confusing and not easy to access if using all; lots of toilets with toilet paper all over the area (squat or seated). (Korea) wide roads and highways and wide pedestrian walk ways; subways are very wide and clean and it is the most extensive network we've seen so far in our travels; some areas are messy especially around the universities, leaflets are scattered on the streets or given away at all places; toilets are easy to find, especially in Subway stations, and are pretty clean. (HKSar) cramped road ways, lots of cars, buses and trams; lots of roadwork and building renovations; clean in some areas; lots of bamboo poles used for scaffolding; toilets can be found in store buildings, not all clean and have toilet paper.
Food - Japan and Korea are easy places to find authentic cuisines for cheap (using the point method). HK, you need to have a guide to help you find them, unless you can read Chinese script.