Matter is a 'Culture' novel. [Idly, I had the thought of a Culture LARP. But the image of my friends sitting in trashcans pretending to be drones was too much.]
Matter races along quite well, and it's interesting in that it focuses primarily on a (shell)world where the main players are a not very advanced technological civilization, relying more on beasts than technology for transport and warfare. So some of it reads almost as a court-intrigue fantasy, though they are all aware of their place in the galactic order of things. As the book progresses, the stakes are raised and the more technological races get involved, leading to a final crisis.
A little heavier on the whiz-bang and action side rather than the nuance and idea side but I certainly got sucked into the story and raced along to the finish.