I am a big fan of the Knopf MapGuides and usually get one for each place I visit, but this was one of the more disappointing in the series. Venice is difficult to navigate and it would be nearly impossible to create a completely accurate map of the city. That said, many streets on these maps are not labeled. There are also a large number of streets, bridges, and landmarks in Venice that do not appear on the maps. I spent a lot of time trying to match the maps against what I saw in person, and found the smaller maps in my guidebook were much more accurate.
There are also several areas of Venice that simply are not covered on the maps, including all of the islands. We found some delightful streets in the western part of Santa Croce that do not appear on any of the maps, and no coverage of the area near the train station or the Piazzale Roma, which are important points of entry into the city. Overall, the maps were just average for what they do cover, and the coverage of Venice needs to be improved.