Reading the other reviews, I'm slightly puzzled by some of the reasons given to dislike this book. One of the main drivers in the book is the concept that information from robot parents is blended together into their offspring. This 'twisting of the metal' is done without much technical detail and I for one think this is fine (how many readers want to read about meiosis in a standard fantasy novel?; or need a diatribe on comparative genomics / syntenics if the author needs a human/orc hybrid?). I for one would be INTERESTED to hear more about the mechanism but it is not essential for the plot; and I'm happy to believe that there is some element of nanotech/silicon-extrusion engineering to the mechanism of 'twisting metal' (blue is a perhaps a clue that it is not just pure elemental metal being 'twisted'). Many of the complaints in the negative reviews are akin to dismissing the Alien books/films because their weaponised / genetically engineered origin is not spelled out in bioinformatic detail ! Suspending disbelief and filling in the gaps yourself is part of the fun in science fiction and I haven't found too much so far that cannot be imaginatively filled in with a bit of creative licence (after all, who would have believed in miRNA's before they were discovered) - I'm only about 3/4 through so far (seriously restricted private reading time) but I came here looking for a sequel in preparation for finishing..
Throughout the thread of the book there is a clear inorganic/informatics equivalent of Darwinian selection (akin to Dawkins meme selection in some ways). To me this is one of the most intriguing aspects of the plot and reminiscent of 'Code of the Lifemaker' - which I recommend if you liked this book (especially the first chapter which is also available as a short story). To balance this, the evolutionary drives of these robots are in some ways more Lamarckian than standard biology permits which allows for some interesting possibilities. It also seems that their general development is more pre-determined than human development which somewhat restricts some of their choices (but doesn't stop potential future meta-regulation of development). I find this all quite self-consistent and I like the discussions of form vs function which manage to fit into (and progress) the plot without being contrived. I also like the shock tactics of making the reader suddenly question their own definitions of life vs mechanism - especially when it comes to the character 'Axel'.
In summary, this is quite a thought provoking book that also has a quite acceptable plot that allows the various characters to develop in parallel and interact (twist) together. It is a tiny bit shakespearian in one or two of its outrageous coincidences but then I'm OK with that..