It was indeed a great novel. One compliment I have- one of many- is that it took artificial, mechanical sapience (usually my biggest turn-off in sci-fi) and made it interesting. Normally thinking machines and AI are the one aspect of science fiction that bores me, but here I was intrigued; while I appreciate characters like Data or the EMH, that's more to do with the individual than their AI natures. But the Sentries were interesting due to being AIs as well as in terms of their individual characters. Another thing I appreciated was that this novel made me self-examine and actually helped me come to a few uneasy conclusions about my stance on AI. In fact, between the Sentries, Titan's avatar, and good old Torvig and the Choblik faith, I found myself very thoughtful in regards to how I relate to the possibility of machine intelligence. I've come to realize that I would probably- sunconsciously, I guess- relate to it as a lesser or even perverted form of sapience, and that this is an intolerance I might conceivably one day have to deal with. So, it left me quite thoughtful.