I read and re-read this book while living in Hong Kong in the 90's, both before and after the end of British rule. Through it I learned of mnay fascinating parts of the place far away from the overcrowded urban areas - for example, the wonderful hills of the northern New Territories, full of trails put down in British days and full, too, of beauty and history. There are a thousand wonderful anecdotes in this book.
The description of expats is very good, surprisingly accurate when at its most funny, too - some expats do not appreciate such bluntness!
There is also a wonderful, very moving account of the millions of Chinese refugees who fled China just in the last several decades to make up the population of today. This is a very sad tale, well told, and helped me understand much of the unpleasant behaviour I encountered on the streets and in the crowds that didn't make sense (or make for tolerance) until I had read this account - I had a far better appreciation for the place after reading this. If you plan to visit/live in Hong Kong, do take this book along. The whole refugee story is very painful (understandably) for Hong Kong Chinese to talk about (it causes loss of "face" to do so), and you will not hear much about it in post-Handover Hong Kong, but a knowledge of it is essential for understanding the place. Despite the city's financial centre-status, most of its residents are poor, and most fled to the safety of British Hong Kong to work in sweat shops, which, tragedy of tragedies, made for an improvement in their lives.
I rank this book up with the other usually-mentioned Hong Kong classics: Timothy Mo's The Monkey King; Bo Yang's The Ugly Chinaman; Austin Coates' Myself A MAndarin and Paul Theroux's Kowloon Tong. All of these will give the Westerner a far better understanding of the place than any guidebook or Culture Shock!-tpe guide.