Anthony,
It's still a worthwhile read, especially on how Napoleon constructed his own image through art and the written word. Dwyer generally does try to present both pro- and anti-Napoleon opinions on the major events surrounding the Emperor (his account of the breaking of the Peace of Amiens is very even-handed to cite just one, basically concluding that the Brits and the Emperor both were equally to blame). But in the end he comes down on the anti side, which is in keeping with his other books and articles on the Napoleonic era, so the Bonapartist historians out there will probably have more than a few objections to Dwyer's point of view.

-Alex