This book describes 'what it says on the tin' as perceived in the second half of the 17th century. During this time England went from the somewhat puritanical Commonwealth (multipractice but still limited tolerance; when many local and regional religious records were not kept or did not survive for eg) to restoration of the monarchy and more traditional, though still changed, protestant Church of England as the State religion: a time of enormous change.
As an amateur researcher of English local history (researcher in a different field professionally) I recommend this book for those researching the subject in two main respects:
1. It is accessible (ie in English not Latin!) and summarises a lot of information that I would not otherwise be able to understand; although word search is of little use, the delightfully termed 'Table' at the back prepared by the author I presume enabled me to find where things were; these books are often the sources of later ones, and thus it is helpful to be able to see this kind of 'original' (even if we can't yet see older originals that are still extant).
2. Just by the nature of content of the book, one glimpses the things that were deemed important to know in the past, and part of the history of historical research and writing. Of course, Dugdale himself was not infallible, but did his best as a man of his time, whatever that may be. His are one pair of the many shoulders on which anyone who writes about the past finds oneself standing.