I used this book as a textbook for a senior-level class in Developmental Biology. Gilbert is the standard reference, and I had used his 2nd edition book years ago when I had Embryology myself. Someone else ordered the book (before I was hired) but I was relieved when I found out that it was Gilbert's text.
However, much has changed since the second edition. One bewildering aspect is that, although development arguably begins at the point of gamete fusion (fertilization), this is not covered until Chapter 7... there is half a semester's worth of material before one even gets to fertilization. This strikes me as too long; many of the concepts that precede it are really best handled afterwards (such as cell-cell signaling). I note that fertilization made its appearance in Chapter 2 of the 2nd edition, so it is not just my personal view that this is the right place to begin -- it used to be Gilbert's!
Beyond the strange choice of sequence, I found that this book focuses too much on idiosyncratic details and not enough on over-arching concepts. For instance, Gilbert spends pages upon pages describing in detail one specific cascade reaction after another, without ever really "zooming out" to generally address the importance of cascade reactions overall. In other words, he spends so much time focusing on the detailed nuances of the leaves on every tree, that he misses the forest.
My students universally despised this book, and complained that it was near impossible to follow or understand. They said that they got much more out of my lectures. But the only difference was that I spent time poring over the book (as I am not really a Developmental Biologist myself) and reading it carefully, and then making outlines of the general concepts that Gilbert was illustrating with his details. I could then present the concepts to the students, and tell them that the book has examples.
I really believe that a text book should be organized around concepts and biological processes, not the details of a thousand examples. Examples will be forgotten over time, and can be looked up in any case, but the understanding of the overall concept is what one most needs to obtain in class, and from a text book. This edition of the book is really just a compendium of examples from the literature, and not a textbook of concepts.
I know that Gilbert is a "standard" text in this field, but I am nevertheless exploring other Developmental Biology texts for next year, because this one just does not do the job that a good basic text book should do.