This is a good book written by an exceptional soldier and historian, however, it's not for everybody. I'll try to quickly summarize the primary obstacles for the average American reader.
First, this is an operational history and operational histories are, by their very nature, boring reads. It is particularly difficult to get excited about the movements of various armies, corps, and divisions when American readers are generally unfamiliar with the geography of Alsace-Lorraine and the faceless commanders of either side.
Next, Sir Michael elected not to translate the oblique French and German quotes of the participants provided to illuminate critical decisions and/or decisive actions. One must assume the British audience of 1961 were well up on their French and German. Most American readers will quickly tire of thumbing through their phrase books trying to figure out what was said.
Finally, Sir Michael must have assumed his audience had a certain working knowledge of the primary cast of characters, places, and events of the 1870 War. For example, few American readers will likely be familiar with the Empress Eugenie or influence she had on her Emporer husband and the French decision making process as a whole. Nor will the average American reader understand such archaic references as "the stone", a malady suffered by Napoleon III, though they will no doubt figure it out in time.
While reading this book, I spent a considerable amount of time online trying to understand the background information surrounding the conflict. Though several maps are included, they are not very useful owing to their inappropriate scale. At $30 per copy, this is a book best left in the public library and consulted when and if needed. If you're a die-hard military historian, then by all means, CHARLIE MIKE. If not, skip it.