This movie was absolutely brilliant.
It was filmed in a manner that makes it seem more realistic than most movies. Each frame is beautiful.
A note on dialect - This movie (with the exception of Leung to his mistress) is in Wu Chinese. Wu is hardly a minor language, spoken by well over 70 million people worldwide. It is spoken not only in Shanghai (the largest city in China) but the surrounding provinces, including such large cities as Suzhou and Wenzhou. It is actually more widely spoken than Cantonese and Taiwanese combined, making it the second-most-spoken variety of Chinese, dwarfed only by Mandarin. (70 million speakers is a lot of people; many national languages in Europe have fewer speakers) However, Wu is not spoken by as many overseas Chinese as are Cantonese, Mandarin, and Hokkien (aka Taiwanese, Minnan, etc), and for that reason less Westerners speak it. (in addition, Cantonese, Hokkien, and Mandarin are all the primary languages of at least one self-ruling political unit, even though the former two have less speakers than Wu)
This is the only well-known movie with dialogue primarily in Wu, and it is based on the 19th century Wu novel by the same name (except read as Wu).