It's a cliche, but this is a curate's egg of a book. I think a reader is entitled to approach a text cautiously when they realise the author feels the need not only for an introduction, but also a preface, an author's note, acknowledgements and a warning before actually getting down to business (he adds an afterword, a note to the reader, and an 'about the author' section at the end for good measure). This sort of thing lends itself to two assumptions: first, the writer might be a wee bit pompous: and second, that the book could likely be shorter, and would probably be better for it.
Both of these are true to some degree. When writing about actual fighting instruction, the book is an excellent primer: clear in both the instructions and the illustrations, usually concise, covering a variety of basic stances and moves, and including a nice range of information (separate sections on sword alone and sword and shield, for example, each containing information on fighting against a variety of weapons - other swords, axes, polearms, etc.) There are other sections that are excellent background information too, informative and interesting.
But for all his knowledge of swords, it's the axes he has to grind that Clements struggles with. His particular bugbears (including theatrical combat, two common re-enactment rules, and the reluctance of Eastern martial artists to fight him) each get a dedicated appendix to themselves. Sadly, this doesn't stop him bringing them up with irritating frequency in the text - particularly the first and last. Nor are these the only instance of a point being laboured. It really bogs down the writing and handicaps what should be a great book.
The author's claims that the book is 'scholarly' are also a bit overblown - in fact I was struck by the relative lack of references in the text, though the bibliography is fair. But, authors do tend to make these kind of claims, and unlike the axe-grinding this shouldn't be a problem for the book's main audience - those interested in learning or refining their knowledge of use of the sword.