Be sure you do know your stuff in Java, or else this book will seem over your head. This is not a beginners book. But if you're a Java developer, or have similar programming experience, this book is 100% for you.
My only quirk with this book, is that at times, it's more of a refrence/comparison, over how to use several key .NET features. And it seemed to jump around a little. So actually I'd probably rate this book a 4.75...but rounding up gives us a 5, which it pretty much deserves.
I highly recomend this book out there for anyone who is NOT a beginner programmer, or comes from a Java background. This book is a MUST read for you.
definitely recommended!