back to my original question, can someone comment on the two cities, not schools ...
Sorry about mistaking your question with lack of information about INSEAD. I see you've done your research.
In terms of city sophistication in Asia, the only city that can beat Hong Kong is Tokyo.
When comparing Singapore to Hong Kong, and while they may be on par in terms of business activity and education (generally speaking, not just HKUST and INSEAD), Hong Kong has much more connections than Singapore and has a stronger emphasis on culture.
Hong Kong has a lot of connections, in terms of infrastructure (the naval freight business has gone down but HK is still the door to/from southern China, it has the world's best airport and a lot of air traffic) and telecoms.
However, another reason why many companies go to Hong Kong is obviously its closeness to southern China (where manufacturing factories are). On the oppositve, Singapore has a strong position with southeast Asia and to some degree Australia, but it's just not as sexy in terms of business.
Culturally, for many decades in the late 1900s, Hong Kong has been THE driving force in Asia. Ask why so many young Teochews from Malaysia don't speak teochew but cantonese instead. Nowadays, the japanese culture has become more visible, but Hong Kong still has its aura. Singapore is a dwarf in comparison.
In terms of gastronomy, Hong Kong food is the world's standard for best Chinese food. Singapore is working hard towards that, esp with a nice mix of cultures.