This book was a really accessible text for immunobiology. I saw some complaints about the subject matter being really all over the place and things not being explained, but I think this is dependent on what your goal is with this book. If you are looking for an immuno textbook to self-teach or leisure read (why would you do that?), this is not that book. One thing about the subject matter is that it is a complicated web of interactions that do not progress in a very orderly fashion. So subsequently, texts explaining it also do not progress in very orderly fashions.
The first chapter of this book gives a very broad overview without much in-detail explanations. Its like one of those maps you see sketched on the inside cover of a fantasy novel. It means nothing to you before you've read more of the text, its there to refer back to later. I found this to be quite helpful because it adds a bit of repetition and because it gives a nice condensed overview that you can then read over when you are studying and see how much of the additional information not included in the overview you remember.
Overall, I recommend it as a good immuno text but I would suggest to be a bit flexible in the order in which you read the chapters and to supplement the text with a course of some kind. Additionally, I have found that many immuno texts focus a lot on patient presentation and particular known types of infection. Perhaps this is what peple disappointed with the book were looking for? This is a biology book, so the focus is less on immunomedicine and pathology and more on immunobiology (like the title says).