Massive, meaty analysis of Turtledove's fascist-Confederacy series here. I gave up on that series about two books back, mostly for stylistic reasons. The blogger takes Turtledove's world-building dead seriously, and I think I agree with most of his conclusions, although I have to say that his assumption, which drives his argument that the British would shift to a Northern alliance in the late Victorian/early Edwardian, that a post-secession USA would build its industrial infrastructure in the same vulnerable-to-Canada fashion as was historically the case, strikes me as flawed. Admittedly, much of the infrastructure is geographically-driven, but there is margin for adjustment. The points about the necessity of militarization of the Lakes are, however, entirely cogent.
Correction: that's no blogger, that's Jim Bennett, late of UPI's syndicated "Anglosphere" column.