A good strong ending to what at times seemed like a never-ending series. I liked it that the story goes beyond the end of the war and into the implications of what it would mean to reconcile parts of the country that have been separate for 80 years.

I had to force myself through this last book of a series that started with such promise. I found myself thinking that I had read all this before... the same characters saying the same lines after the same battle...
Turtledove's attempt to mirror the RL WW2 in this series is part of the problem, IMHO. The CSA is clearly modeled on the Third Reich, right to the "Asskickers" (Ju-87 Stuka is RL) dive bombers with their sirens and the camo-uniform on the special Guard units of Featherstone's version of the SS. Then, of course, is the genocide of the CSA's black population.
Then there is the world stage - something only skimmed over by Turtledove in the series. How on earth did two powers - the abbreviated U.S. and Germany - stand up to the might of the U.K., France, Russia and Japan? A more balanced or fluid international situation may have been more credible.
Sure, in the RL, the nations of Europe fought two horrible wars between 1914 and 1945, but the First war so greatly weakened them all that it influenced the Second - France was morally and spiritually exhausted, Britain was financial exhausted. Turtledove has four major wars fought within 80 years - wars that each devastate all the nations, kill untold numbers of men, and yet each nation seems to have the wealth and resources to bounce back for another round.
And the characters? I don't recall any new ones entering the fold in the past two or three books - and thus the seemingly repeated dialogue and situations among characters with which nothing really new happens - the doctor mends another broken body, the General frets over another break through, the naval captain sinks another submersible. Yawn.
There is the lack of building towards a climax; once you realize the war is essentially (prior to the nuclear weapons) just a relocation of the RL WW2 - from the surprise attacks on Ohio (Poland) to the battle of Pittsburgh (Stalingrad), to the use of rockets (V-2's) and new wonder tanks (Tigers & Panthers), there is no sense of "what may happen next"... even the plot on Jake Featherstone's life in an attempted coup seems to have been thrown in as an afterthought - there is no prior meetings of the conspirators, nor any opportunity to describe the mindset of those involved to orchestrate the plan, it is tossed away for a few pages of trite action.
Again, I followed this series from the start, and looked forward to every new release until it seemed to descend into an endless loop.
A disappointing end to a series with great promise.