I've been hoping Conway Morris would write a book like this for some time now, since the past decade has been so eventful in terms of convergence. As a catalog of recent findings and a jumping-off point for further study and debate, it's excellent. It would be fun to teach a class on the different chapters and dive into the evidence with advanced biochem students. I have a nagging suspicion that maybe a quarter of the cases Conway Morris presents as scientific evidence for convergence may have other explanation, but as long as a majority of the evidence presented here "sticks," you have a pretty convincing hodgepodge of data that evolution has a deep structure that it repeatedly finds.
My main issue is with the lack of organization. There's so much here and it's presented at such a high level that some pages read like a list rather than a sustained argument. That's fine -- I could use a list like this very much, thank you -- but it makes for slower reading especially by a non-biologist. There are connections made from chapter to chapter, but they are abrupt and don't have a deep structure themselves, except that the more complex matters of brains and minds are put at the end of the book. Conway Morris is entertaining as ever, and the balance of writing far favors wit over clarity. There's a place for that. As long as you expect that, I think you'll find a lot to think about here. Not sure if it helps convince a hostile audience, but this non-hostile audience member is glad this book came out, and it helped point out a few dozen papers I was unaware of as well.