As someone who has lived in Hong Kong I have to say it really made me appreciate the city more playing this game, I got so much nostalgia exploring and looking at the city.
Also the small details like Russian hookers (yes they do exist in HK), the bar scene hood (I assume it was meant to be like Lan Kwai Fong where all the expats hang out), the highways, the warehouses, high rises, so many small details which really added to the game. I can't speak for everyone since those who have spent significant time in Hong Kong are a small portion here but I really appreciated the attention to detail. Although the Triad influence is greatly exaggerated I understand it was to make the game fun and exciting.
If there will be a sequel my biggest hope will be that the game expands to the other side of the bay and you can explore Kowloon which has it's fair share of shady areas/poor neighborhoods and some nice areas as well. Also maybe add in the MTR public transport system? I kept looking for an MTR station (would have been a nice way to get around) and finding taxis in HK is incredibly easy compared to the game sometimes.