Have just had a lovely week based in Sorrento - this book gave us all of the information that we needed to explore the area. Bus and train communications are very good (though sometimes very crowded) in the area so, armed with the book +bus & train timetables, we were able to see a lot in just a week. As well as seeing Sorrento, we visited Herculaneum, Mount Vesuvius, Pompeii, the Amalfi coast and Capri; in each case the book provided us with highlights and other information on which to base our itinerary.
Why 4 stars rather than 5? Any travel book is likely to be out-of-date the day after it is published. So, for example, some of the recommended highlights in Pompeii weren't actually accessible. And the small-scale map of Pompeii wasn't easy to follow - though, frankly, nor were the maps that you could buy on-site! Still highly recommended, even though we only used less than a quarter of the book.