This was the only guidebook I purchased for a trip to Malta. It was helpful, gave a good general overview of the most interesting sights and overall helped us to feel we saw Malta.
The pluses: the book included walking tours of a number of cities, including Mdina, Victoria and Valletta. These were interesting and helpful for do-it-yourself explorers. The first couple pages (which are in color) gave a useful overview of different types of sights and activities.
I loved the walking tours, but the information given was minimal. The book was not hefty (around 150 pages overall). Additional information and history could easily have been added here.
The entire bus system was redone in mid-2011, about 18 months after this book was published. All bus information is therefore now out of date. The maltese bus system is easy to use, but don't rely on this book for information.
The book included some more detailed descriptions of locations (St. John's co-cathedral), but could have easily expanded on those. I don't need a full history book, but this could easily have given more information without being a dense tome.
Overall, it's a useful book and if it's you're only guidebook for Malta, you'll be fine, but some improvements are definitely possible.