Eras are conveniences, particularly for those who never experienced them. We carve history from totalities beyond our grasp. Bolt labels on the result. Handles. Then speak of the handles as though they were things in themselves.
Good, but not great. As much as I love learning about the world or lore of a particular book, there were so many mundane details that it seemed like the first 50-60% of the book was world-building. I appreciate the use of an immersion technique for context, inviting the reader to put together the puzzle pieces. Only at about 70% of the way through did anything of real consequence start to happen and even then it was frequently punctuated with chapters of momentum-killing detail.
The prose is comprised of very long sentences, often dripping with extra descriptions. The tone is frequently neutral, I can't remember a time when the overall pace of the reading sped up or slowed down. I guess that's appropriate given the context of the characters we follow, none of whom are explosive themselves. The best part was probably the protagonist Flynne who serves as a perfect anchoring point as we jump back and forth between the pseudo-present and the future.
The ending was satisfactory, but maybe a little rushed. Again Gibson puts the details out there, leaving us to decipher the results of the climax.