Life changing book. Most of the suggestions (if not all) are not shocking and are at times quite common sense, but, it shows how personalities and emotion get in the way of rational thought. Reading this book is likely to make you better consciously aware as to when you are making poor decisions which involves people. Carnegie uses some fantastic examples throughout history to illustrate his points. The book has already changed how I interact with people, especially in hostile and challenging situations.
Despite being excellent, the book can be a bit repetitive at times, although I appreciate that's probably to nail the points home. I also think some of his suggestions are a bit simplistic. Each chapter is often around five pages and there is no room for discussion. Sometimes Carnegie raises more questions than answers.
However, these are nit-picks, and I don't think the book was intended to be a long and indeed protracted discussion. Nevertheless, that doesn't stop me from finding it a bit frustrating, at times.
Overall: Very good, but a little too simplistic for me to give it a 5 star.