3/5 (chosen by random selection from my unread pile)
Read as an amateur on the time period. The book covers the wars around the Baltic from the fall of the Livonian Order to the end of the Great Northern War between Peter the Great of Russia and Charles XII of Sweden. The main topics are the various campaigns and wars and how they were fought, the changes in all major aspects of the military (tactics, equipment, organisation etc) over the course of the period and how the relationships between state and military changed over time for the contenders (mainly Denmark, Sweden, Poland-Lithuania and Muscovy/Russia).
In terms and information and arguments the book seems pretty good to me, but I don't know a lot about the time period. The main reason I'm only giving it a 3/5 is that it is very heavy on the names of people (leaders, generals, political figures), places and also numbers - things like the percentages of foreign mercenaries in leadership positions or the demographic makeup of different militaries over time. So I found it rather hard to follow at times which limited how much I got out of the book.