I don't really like to review books online, as so much of the review is subjective. I'll make an exception for the Fat Duck Cookbook. It's that good.
First off, the recipes are amazing... as they should be, since they are the exact recipes used in Blumethal's world-renowned restaurant. They are also elaborate. If you decide to make one, think of it as a quest rather than as a traditional recipe to be made in an afternoon - most of these will involve a good deal of searching for ingredients, a large amount prep time, and sometimes specific equipment ranging from just hard-to-find to hard-to-find AND really expensive.
Even if you don't make the recipes... even if this book didn't HAVE any recipes, it would still be great. The photos and art are nearly worth the asking price on their own. Huge, glossy, detailed pictures of some of the most intricate and intricately plated dishes I've ever seen. Enough beautiful abstract art to justify it as a coffee table book in this respect alone. Furthermore, each recipe is accompanied by an essay on the development of that recipe and thoughts on exactly what makes that recipe work, or why previous iterations of it did not work as well. You don't have to make the recipes to find this type of commentary useful.
Then there are the other two thirds of the book. One is somewhere between an autobiography and a treatise on the author's culinary formation and thought process. Sound dull? It isn't. In part because of how well it is written - relatable, brisk, to the point. Even more so because of Blumenthal's enormous insight into both the art and science of cooking. He explains his process in creating and perfecting his food using specific examples. He alludes to the science he uses whenever applicable - his explanations are neither dumbed down nor are they a single bit more complicated or hard to understand than need be.
I found myself using a highlighter while reading it to mark things I wanted to look up later.
And as though Blumenthal somehow knew about my highlighter, he included as the last third of the book an index of terms, descriptions of equipment and ingredients, and essays on the scientific aspects of cooking and eating. Essay topics range from emulsions to how taste and pleasure are related via the brain. Most of these essays are not by Blumenthal - they are written by scientists who have influenced Blumenthal and added to his understanding.
I should point out, I guess, that this book is probably not for most culinary novices. The pictures might go over well, but the rest will be like showing calculus to someone who's still learning to add. But for pros and dedicated amateurs, I don't think a cookbook gets much better. It's inspiring, beautiful, and informative. As much as it can teach about the science of cooking, it has just as much insight into the art of cooking - what associations, effects, textures, contexts, and flavors make a dish great. In this way, it is just as invaluable to the classical cook as the cutting edge one. It prompts you to look at a dish and wonder 'In a perfect world, what could make this even better?' And suggests that whatever the answer is, it may well be possible.