Hello. I am interested in how the Istanbul section of the Mediterranean Cruise Ports book compares to the standalone Istanbul book. (I'd also 'd be interested in how the Athens chapter compares to the Athens section of the standalone Athens & the Peloponnese book if anyone is familiar with that). Would I be losing out on any material (such as walking tours) by getting the Cruise Ports book instead of the Istanbul book or is the material the same? Many thanks!