In general, I like Bear's work. Not as much as I like, say, Cherryh or Vinge, but I do like it.
This book disappointed me. Bear went with an unreliable narrator and a narrative style that was high on revealing the character of the narrator...and low on readability. Sorry, Greg. I simply found this book hard to get into, hard to understand and hard to read. The plot is interesting enough...a generation ship on which a string of very bad things happen. But I could really not get past the narrator.
I can't give it more than three of five, I'm afraid.