Roland Barthes was a man who lived and breathed semiotics. He applies Ferdinand de Saussure's theory of the sign to everything, and when I say everything, I mean everything. A short list of topics the collection of writings in the book touches on is art, literature, film, photography, architecture, writing, striptease, wrestling, tuberculosis, cooking, teaching, science, love, and, sex. Barthes wrote about every pit stop his mind came to, and no thought of his escaped the structuralist binary of the signifier and signified, except when he tried to slightly modify or critique it.
As a writer he is maddening. Essays tend to start off lucid and devolve into insufferable obscurity. He is either a beautiful writer who communicates a unique perspective through some of the most apt figurative language I have ever read (his essay about the Eiffel Tower and the excerpt from the Pleasure of the Text come to mind) or he gets lost in a web of fragmentation, allusions, jargon, and words that probably don't need capital letters (I skimmed through much here but the excerpt from A Lover's Discourse is the only one I could not force myself to finish). I don't know how much of this is to do with translation problems, but all of the hallmarks of bad postmodernist writing are here, so I think it is fair to hold Barthes in suspicion of obscurantism.
That said, there is plenty here I wish to revisit. The best sections to my mind were the excerpts from Mythologies ('The World of Wrestling' and 'Myth Today'), Image-Music-Text ('Introduction to the Structural Analysis of Narratives', 'The Third Meaning', and 'Writers, Intellectuals, Teachers') and Writing Degree Zero. The excerpt from Roland Barthes by Roland Barthes gives some humorous insight into who he was a person (he hated women in slacks, apparently), but I think his project is best summed up in his inaugural lecture at the Collège de France, where he speaks with relative clarity about academic freedom, the power of language, and what semiotics means to him. The events of May 1968 in France were a sign that the old institutions had fallen and ushered in an era of "gentle apocalypse". Like Susan Sontag in her introductory essay, I think this is a pretty good way to describe the tone of Barthes, who seems to have found a great opportunity for playfulness in a somewhat nihilistic intellectual milieu and lived it to its fullest extent.
One notable omission is 'The Death of the Author' which is his most famous and (to my mind) best essay. Perhaps it is not here because it is so widely published elsewhere.