These are dense books. Stephenson has done his homework and it shows. Perhaps a little too well. I was often left feeling like I had walked in at the end of an in-joke, particularly in the first volume, Quicksilver. It doesn't help that this first book is split between three different narratives and two verb tenses: Daniel in the present tense (sailing from a newly-independent USA to Britain), Daniel in the past tense (flashbacks to his friendships with Newton and Leibniz, and the volatile politics of Britain from the Restoration on), and Jack and Eliza in the past tense (their adventures running in parallel to Daniel-in-the-past). I'm usually good at juggling multiple storylines and protagonists but this one led to headaches. Remembering who's who, how they know each other, which narrative they belong to... ugh. The dramatis personae list at the back helped a bit - but not much.
I couldn't get into Quicksilver; I had to keep breaking off to read something else and give my brain a rest from trying to make sense of all the historical allusions. Daniel is the nominal lead in two of our three narratives but doesn't do much except run into famous figures from history: Newton, Leibniz, King Charles II, the Duke of Marlborough, Blackbeard. And aside from the Logic Mill project and Eliza's coming from a non-existent country with an unpronounceable name (this latter bugged me throughout the series; why make up countries?), I didn't understand why this was filed in the sci-fi and fantasy section.
The Confusion is a more straightforward adventure story, with Jack and Eliza taking the lead roles. They are much more dynamic protagonists than Daniel; Eliza even manages to make explaining the stock exchange entertaining. There are no flashbacks, as the narratives occur contemporaneously with each other, and either there aren't so many of those historical in-jokes, or the ones which are there I understood more readily (there are long sequences set during the Irish wars of a certain King Billy, for example). It's in this book that the McGuffin of the gold comes into play (I don't want to say more than that for fear of spoilers), and with that, the plots start to cohere and the characters cross each other's orbits in a less random manner - another reason why I found this an easier book to enjoy than Quicksilver. Plus: globe-trotting multinational pirates!
But I still didn't understand why this was in SFF and not General Historical Fiction. Sure, the gold is alleged to be [REDACTED] but this was an age of quacks and fakes, as well as genius. The narrative doesn't confirm that the gold really is what some characters believe it to be...
...Until (maybe) you come to the end of The System of the World. Now initially I had the same problem here as with Quicksilver: I couldn't get into the story and had to keep stopping-and-starting in order to maintain my interest, particularly during the Tower of London sequences. But now the gold becomes the key force in everyone's plot line, and as the Hanoverian succession comes closer, the political landscape became much more recognisable to me. Daniel, who in the first two books was a mostly passive character - someone who has stuff done to him rather than doing stuff - comes into his own at last, taking the lead in a tale of political conspiracy, economic sabotage and that finally-maybe justification for the SFF label.
Except... when you've read thousands of pages of more-or-less regular-flavour historical fiction, does a few hundred pages at the end really change the genre of the whole? Do I even want it to? I had been waiting for so long for the sci-fi/fantasy element to become a clear factor - and when it did, I preferred not believing in the gold.
So in the end, I don't know what to make of The Baroque Cycle. Headache-inducingly-widescreen historical adventure with the vaguest tint of steampunk and some alternative geography? Hmmm.