Ok, I really want to get here and write a review, because all of the reviews of this series/book that i find are complaining about how he goes on and on about walking through London, traveling across Europe, daily life in Paris, Versailles, Germany, The Netherlands, Cambridge (England), Massachusetts, and so forth. For me, this was one of the best parts of the series. The fact that he provides so much detail puts me right in the middle of things, and helps me to visualize the world of this book in a way that most books do not accomplish. Furthermore, while he is describing the current world of the main characters, he's also conveying other information to the reader about what will happen, providing backstory, and accomplishing other tasks necessary to the story. Most books' main goal is to convey the plot and perhaps encourage you to have some feelings for the main characters along the way. But this book, besides doing these things, gives you the whole world. Except, instead of being a fantasy world of the future, it is the *mostly* real world of the past. Yes, there is the alchemy thing that is a little fantastical which technically makes this book science fiction, but practically speaking, it is a work of historical fiction.
I do think it helps to have a basic knowledge of European history from, say, the times of Henry the 8th up through Napoleon, because this knowledge helps you to follow the story more easily, and to get some of the jokes or subtle stories, which sometimes hinge upon the reader knowing what is ultimately going to happen. This applies to big events but also little things. For example, the transition from using coins as money to paper as money provides one of the undercurrents of this book. At one point, one of the characters has to explain to another what a banca is, because it is a new term for them. I'm there reading like, "haHAH and now we call them BANKS!", and that kind of thing.
I also believe that, if you are a reader of Stephenson who is coming out of Snowcrash or Cryptonomicon, and you are looking for more of this, you may be slightly confused because, although he continues the themes such as history of the world through the lens of science, economics and computer systems being indelibly intertwined, the guy who isn't a scientist but understands scientists better than they understand themselves, characters who just do stuff without worrying about it or sweating at all, etc, since it is based in the late 1600s-early 1700s, all of these themes are (obviously) addressed in the context of that time, which means theres no new tech funness. But I don't really care about new tech, so its fine.
I'm a reader whose favorite genres are historical fiction and science fiction, and I think one of the reasons I love this series so much is because it is successful in both, as well as being written carefully and with great detail. If you have the patience to let yourself get into it, I say go for it.
Honestly, it took me a while to even understand what the what was going on my first time through. But I'm ok with that - I eventually got there. Right now I'm on my second time through, via audiobook, and the audiobook does help a lot because it makes some of the denser dialog easier to digest. If you want to read it but are struggling, this might be the way to go.