Notes on this book, by chapter:
Chapters 1-20, from preliminary algebra through linear algebra, analysis, and ordinary differential equations, is written very well and is great for learning or reviewing the material. Perhaps one of the best presentations of the material I've seen.
Chapters 20-25, on partial differential equations, the calculus of variations, and complex variables, was markedly worse than the first twenty chapters and most readers would probably benefit from going through those topics in another book.
Chapters 26 & 27, on tensors and numerical methods, is fine but a little too concise. Would be worth reading other books on the topic just for getting a good sense of them, which the book sadly didn't do a great job of doing.
Chapters 28 & 29, on group theory and representation theory, suffers from being both too long and difficult to follow because it relies on verbal descriptions rather than introducing a system of symbolic logic and discussing the topics within it using that system. There were easy 10, 15 page sections in those chapters that could have been replaced by a half page of logical statements.
Chapters 30 & 31, on probability and statistics, are a bit disappointing. They start from very low levels (Venn Diagrams) and introduce a symbolic logic system for translating those Venn diagrams into the level that people can understand things like Bayes' Rule. However, it lacked some things that would be good for probability students to learn, like a rigorous discussion of the Kolmogorov axioms, various conceptions of probability, and the underlying assumptions behind statisticial procedure.
Nonetheless this book is a masterwork, the first 2/3rds are an essential read and the last 1/3 provides some information on the topics that would be better supplemented with other works. For anyone considering reading more into the higher mathematics and their application in the sciences, this book is well-worth picking up.