I really love these books. 'Introducing Barthes' is typical of the approach of the other books I've read in the series. It sweeps wide and fast without being simplistic, reveals countless insights in a chatty style and skims over the deep detail to give you 'the gist'. The images throughout break the text down nicely and rooting the meaning firmly in one's memory. Read it in a day and have a solid basis for further investigation.
The 'author's warning' was a particular nice touch in this book, where Thody gives a humble, honest and self deprecating footnote to a beautiful book.
My major criticism of the series in general is the lack of references throughout. The 'further reading' section doesn't help that much when you're wondering where a specific quote or concept came from, but it could be argued that adding footnotes throughout would clutter the page.
One irritating facet of this book is the incorrect index. Every page number I've looked up has been incorrect by one or two pages, hence the reduction of a star.