Longer review later. As to the actual substance, Scharlemann gives a lucid comparison between Aquinas's system (faith formed by caritas, caritas being a moral structure aimed at a supernatural end) and Gerhard (faith as a response to the preaching of the gospel and the terrors of the law).
The actual difference, and difference it must remain, between the two, however, is not quite so crystal clear. Gerhard still accepts much of the moral structure of Aquinas, and Aquinas concedes that caritas must be formed from outside the closed system of nature, otherwise he risks Pelagianism.
The book was written at the height of the Neo-Orthodox age and reflects some of the nonsense (maybe literally) in terminology. We see words like "dialetical" and "confronting the Yes and No and the Yes in the No), none of which actually advances the discussion.
The author's goal is commendable, though, in getting Protestants to see that still claim much from Aquinas.