I thought this was a fairly decent, and above-average offering, from the Classic Beer Style Series. My problem is not so much with the author, or the book, as it is with the somewhat underambitious slant of the series as a whole ... it aimed (back when it was first published) a bit lower than it could have.
Although a bit too brief, the author of this particular volume (book 6 of the aforementioned series) does overview the basic elements of the region: the history of abbey brewing, the primary yeast & microflora strains, specialty ingredients (candi sugar), the role of temperature in stimulating the production of esters and phenols, etc. The author also includes some information on certain advanced techniques: such as dual-strain use (1 for fermentation, one for bottling) for high gravity styles, as well as helpful appendices including a glossary of technical terms, a series of basic no-frills recipes for each of the major Belgian sub-styles, and brief survey of commercial examples.
It's a good, if unspectacular, book.
I read this book back around 1996, and I've made more than a handful of Belgian sub-styles so far ... none of them taken directly from this book, but I definitely relied on it for some general guidance when constructing my recipes (in accordance with stylistic parameters), and also in controling my fermentation temperatures.