As a planning guide, it is thoughtful and sensible. Certainly, there is a fair amount of sound, practical advice offered. Refreshingly, there are numerous pointers reminding and advising one that the most beautiful or elegant weddings aren't necessarily the most expensive ones.
As an etiquette guide, it is weak and the advice offered is too patchy to be relied upon.
John Morgan offered more detailed, much finer, and far wittier wedding etiquette advice in Debrett's New Guide to Etiquette and Modern Manners: The Indispensable Handbook.