I read it many (maybe 15 or so?) years ago. I actually quite enjoyed it and thought it one of his better works. I kind of consider it his "middle period", after many of his classics were written but before his accident and sobriety when a lot of his writing went downhill.

And, I agree with your comment in the response above, for some reason the book is never really mentioned by people and I have even heard some people over the years say they didn't like it. I'm not really sure why. I remember it being quite a compelling read.