I just finished reading it. Overall it is worth the read because unlike Berkshire, for which there are dozens of books, there are almost none that mention huge companies that avoid the spotlight like Brookfield. This is about the Toronto branch of the Bronfmans (the sons of the lesser Seagram's founder, who were not allowed to work in the liquor biz) as opposed to the Montreal Branch (the son's of the controlling founder, who worked in the booze business). It covers Brascan, Edper, Hees, and several other affiliated companies. There is an org chart in the back of the book because the web of interconnected ownership is hard to keep track of.
The GOOD: it's a thorough and balanced book. Neither a puff piece, nor a hit job, it's long and well-researched and give a good history of the founding of the Bronfman's empire until the 1980s. If the corporate culture at Brookfield remains like the culture back then, I'm glad i'm an investor and that it's a part of the corporate DNA.
The BAD: because there are so many companies and so many deals, it's hard to keep track of all the players and most of the deals aren't discussed in any depth. Given how large the company is and that the book spans decades, I don't know how to improve that but a deeper dive into a few deals would be nice. There are several side trips into things that don't add a lot (like discussions about their philanthropy and support for the arts), which are okay but not the show I came to see. Also, the book was written by a pair of business journalists, so it's very well researched, but reads like a very long newspaper article.