I was totally pumped when I found this book at the library. We finally get to find out where the Omegas come from.
The good was, his prose has improved significantly since The Engines of God (general quality of the novels go up and down through the series, Odyssey was probably the weakest and EoG is still the strongest IMO) and it was a passable read. However, I have to say I was kind of disappointed in the execution.
1) The pacing was not very good. The book dragged a lot through the first half, and then the second half when the actual interesting stuff was going on felt quite rushed. It was like he had writers block and wrote a bunch of fluff, and then realized too late he was running out of room for the meat. The book would have been much better if the part devoted to the actual expedition to the galactic core would have, you know, covered most of the book. It was like reading a book about Cortez's conquest of the Aztecs where literally half the book took place in Spain before he set sail and was all about describing his preparations.
I was especially annoyed with the exploration of Sigma Whatsthenumber being accomplished in all of maybe one chapter.
2) I'm starting to get annoyed with some of the repeatitive stuff he pulls in all his books. Like the "I will throw in a random fatal animal attack to artificially pump up tension and drama" trick. He's done that in, what, three books now? Not to mention the whole "I will throw a crew of inadequately trained underequipped people at the worst the cosmos can offer" thing. Something like the first voyage to the galactic core should be done by trained astronauts, or at least professional scientists, not some crew of amateurs. Especially since he has a tendency to make said undertrained amateurs do stupid stuff just so they can get in danger, because apparently people getting killed pointlessly and stupidly = moar drama and tension to him. Rudy I'm talking about you.
3) Cauldron is where we finally get to answer the central mystery of the series; where the Omega Clouds come from. Frankly after reading it I'd rather it stayed unanswered, because IMHO the answer was really lame.
Spoiler
For the love of God, why couldn't he just have made the Omegas Beserker probes? It would have made vastly more sense. The whole thing fits together perfectly. You've got the Omegas, which are obviously designed to fuck up civilizations (seeing as they attack right angles). The hedgehogs are obviously built by a race that's trying to trap and kill them. I mean, they're giant antimatter bombs covered with right angles designed to lure Omegas in and then blow up when they try to destroy them, how does that not scream "booby trap"? And then in Odyssey he drops that there's some physics experiment humans were about to perform that might have destroyed the entire universe, and only some aliens coming along and blowing up the facility before we were stupid enough to turn it on stopped it. Which sets up a pretty solid motive for someone wanting to prevent technological civilizations from existing. You have to keep everyone else too primitive to do the doomsday experiment.
But honestly from the moment I heard that "art" theory I just knew he was going to make it turn out to be something like that.
Also I found the bit with Smith's race to have rather disturbingly luddite undertones (lol we shouldn't develop immortality), but I might just be reading too much into it.
Anybody else follow the series?
And it wants to steal their ship to escape. 
I can't think of any rationalization.
