Have patience with this book; try to get at least a few chapters in. After that, it's not bad. Those first few chapters, though, are a very tough read. If I hadn't already read several Brown books, I'd have stopped there. The first chapters exhibit stereotypes left and right, including particularly offensive treatment of lesbians. Every few pages I'd think of giving up in disgust, but kept searching for a sign that this was just a character viewpoint we were seeing. That was never clearly expressed, but after a while the offensiveness toned down (though quite a bit of stereotyping remained). The protagonist, Halliday, seems otherwise likeable, but we never really see any indication that his viewpoint has changed - he just uses milder terminology. There is a chapter from a lesbian's point of view that is much more bearable, so perhaps it really is a just an offensive trait of the character rather than the author.
Potential bigotry aside... This is a straightforward detective story with SF elements. There's nothing here you haven't seen in one form or another, but it's put together fairly well on both genre fronts. There are moments of dialogue or word choice that seem to betray Brown's non-NY origins, but they're minor. (I do wonder why so many non-American authors seem to feel compelled to set their stories in the US, but that's another issue.) The story itself works fairly well on plotting, character, and story, and the mechanics are good. In fact, in some ways, the story is more complete than some of his later more successful work.
If you're a fan of SF detective stories, by all means give this a try. If you can make it past the first two chapters, you'll be okay. If not, try some of Brown's other work - Helix, perhaps. I'll be going on to the next book in the series because... well, because I already have it, and because I know the stereotypes are not the whole story - just a (substantial) barrier to it.
Fair number of typos.