Key highlights and reasons for the positive rating of this book include:

1. In-Depth Exploration: Daniel Ammann conducts extensive research to provide readers with a comprehensive and intimate portrait of Marc Rich. The book traces Rich's journey from his early days in Eastern Europe to his ascent as a major player in the global commodities market.

2. Complex Character: Rich is depicted as a complex and driven individual who possessed a unique understanding of the oil trade. The book delves into his intelligence, ambition, and ability to navigate the intricacies of international business.

3. Historical Context: Ammann effectively places Rich's life and career within the broader historical context of the oil industry, global politics, and economic developments. This contextualization enhances readers' understanding of the impact of his actions.

4. Legal Drama: The book provides a gripping account of Marc Rich's legal troubles, including his controversial pardon by President Bill Clinton on the last day of his presidency. The legal battles and political intrigue add a layer of drama to the biography.

5. Economic Insights: "King of Oil" offers insights into the dynamics of the commodities market, the complexities of oil trading, and the strategies employed by Rich and his company, Glencore, to achieve success.

However, there are some aspects of the book that readers may find less appealing:

1. Limited Personal Perspective: Marc Rich was notoriously private, and the book relies heavily on the accounts and perspectives of others who knew him. While it provides a well-rounded view of his life, some readers may wish for more direct insights from Rich himself.

2. Controversial Figure: Marc Rich's business practices, including allegations of tax evasion and trading with embargoed countries, make him a controversial figure. Some readers may find it challenging to sympathize with or fully understand his motivations.

3. Complex Subject Matter: The intricacies of commodities trading and the legal battles discussed in the book can be dense and may require some background knowledge or patience on the part of the reader.

In conclusion, "King of Oil" by Daniel Ammann is a compelling and well-researched biography that sheds light on the life of a highly influential but polarizing figure in the world of commodities trading. It offers valuable historical insights into the oil industry and the challenges faced by individuals who navigate the complex and sometimes morally ambiguous world of international business. While some readers may grapple with the ethical dimensions of Rich's actions, the book provides a thorough examination of his life and legacy.