I've always like Harry Turtledove, particularly the world war and great war series. Unfortunatley, this latest series fails to live up to expectations. I find the central plot, the war between CSA and USA, is nothing more than a rehash of Nazi Germany's invasion of Russia. I strongly feel that in an alternative timeline, one should not follow genuine history so closely, after all, what is truly alternative about that?? The plot also does not seem to be true to itself as much as I feel it should be, for example, despite being an obviously unpleasant person, Jake Featherston at least acted within the boundries of reason, perfectly capable of listening to others when they told him an obvious truth. However, in Drive to the East, he suddenly, without explanation, becomes completely insane, utterly incapable of following the advice of a General (Bedford-Forrest) that he has previously shown a great deal of respect for!
As for the genuinely alternate stories, those of the occupation and Canada and the Mormon uprisings, one finds that they are given nothing more than sideshow status, with very little detail of why the Mormons are so militant, or exactly what is happening in Canada.
Having said all of that, I will buy the final two books in the series on release, no doubt with great anticipation, I only hope Mr Turtledove's imagination enables hime to tell a genuinely alternative history the next time!!!