For about the first two thirds of this book—the sections of on the Phaedo and the Parmenides—I found Lampert to be convincing and insightful in his analysis of those two works. Though I do not think I fully understood the second part, because the Parmenides is terrifying, I think I understood the general structure of the Socratic turn as he was laying it out. In the last section, however, on the Symposium, the wheels fell off. I'm not really sure what he suggested Socrates learned in his conversations with Diotima, nor do I see how it is the fulfillment of the second two parts of his "becoming Socrates." As he sketched it out, it seemed like the Symposium would show how Eros played a role in the human mind's structuring of the world, and then how that understanding informed Socrates' turn to human opinion. That may be a bad summary, but up until then it seemed like he was making sense.
The section on the Symposium, however, didn't seem to take up the threads Lampert laid out, and on its own terms it was somewhat confusing to me (maybe I just didn't understand it, I don't know). I'm not even really sure what Lampert thinks Socrates learned. The portrait that Lampert paints culminates in him declaring that Socrates and Nietzsche were in fact the same, more or less, and that they believed the same things about the most fundamental matters (hence the Nietzschean phrase there)! That doesn't strike me as right, and in general Lampert seems to be at pains to make Plato/Socrates cohere with Nietzsche's view of them. I wonder if he could have come to a more coherent conclusion if he tried to understand them more on their own terms, and not in terms of a "Nietzschean Philosophy of History." That kind of need to make Plato/Socrates fit with Nietzsche also manifested in him trying to make them fit in with (i.e., not be fundamentally different from) people like Parmenides and Homer as well. I found those arguments more convincing, but still they rubbed me the wrong way somehow.
There is a lot in this book that is good, especially its interesting discussion of the dramatic dating of several of the dialogues, but I'm not sure a) if it accomplished what it set out to do and b) if what it wanted to do in the end made sense. I was really liking the book, and so it's a shame it went off the rails. I'd still say it is worth the read, however.