This book is by a very strong player who has been willing to take up the Scandinavian as black at the highest levels of chess. For that reason alone, it would be foolish to ignore this book. It is a highly complete and up to date book (2010) which easily replaces the Wahls (1997) book which was only published in German.
Certain obscurities have been left out, for example the Anderssen Counter Attack is not covered. But the Mises gambit is covered, as are delayed attempts by white to play b4. Unlike Wahls (1997) who completely dismisses the Blackmar-Diemer Gambit, Bauer (2010) simply says that though it is unsound technically, it can be dangerous OTB. I should mention that 2...Nf6 (the so-called Portugese) is not covered at all. However, last time I consulted Fritz about this 2...Nf6 did not look like black's best try in the Scandinavian anyway.
Personally I am more interested in this book for various game plans for white against the Scandinavian than for black. Although the book is technically written for black, there are lots of interesting ideas for white.
The book takes the main lines of the Scandinavian quite deep as one might expect from such a strong player. However, there are lots of early deviations for both sides provided, and with first rate analysis.