For readers of his other works the format is just the same as before i.e. telling the stories via generations of families with the pluses and minus associated with it. In my case the gripe would be the the disappearance of a character whose exploits I particularly enjoyed.
Nevertheless, the real story is about Dublin and I believe the author has managed to create a much more interesting and detailed picture of Dublin life (and that of counties) than in "London". This may be because Dublin is smaller and thus the reader is able to keep better track of unfamiliar places and how they evolve over time. Either way, it is very well done.
Unfortunately, much of the early parts are comprised of patchy historic records and thus the author has scope for poetic licence which is used in abundance. As a result the book could have done with a bit more editing at the beginning to prevent it drifting. This is in stark contrast to the harshness and succinct writing towards the end whilst Ireland was under the English Monarchy and clearly more historic literature was available.
I would recommend this book just for a better understanding of how the English asserted their dominance on foreign lands by encouraging the local power brokers to sign up to something they didn't really understand the full consequences of - a ploy used again and again during the building of the Empire.
All in all a great book and I look forward to part two which I hope will continue in the same vein as part one finished.