Well, I've said my piece, and I don't want to drag the thread off topic any further.
I actually wasn't crazy about Harbinger
when I first read it, because I felt it was too dark. But I think it works better in the context of the books that follow, once it becomes clear that it's just the beginning of a journey of redemption for most of the characters. They need to start out in that initial bad place so they can rise above it. So I'm not sure how to rate the book in isolation.
Once I get the final book, I'm going to have to find time to reread the whole series from start to finish.