3 stars for writing and 1 star for structure.
I can appreciate the well rendered voice and harsh vision of 80's hedonism among Hollywood rich kids, but I wouldn't call this a good book. Some of the writing is good; some of the characters (mostly the protagonist) feel real; some of the scenes are evocative, especially when intended to be disturbing. My biggest complaint with the book is that it feels like a collection of vignettes. If, like me, you value storytelling, you might not like this book. It has no discernible plot, no character arc, no catharsis or growth or crisis. It reads like a high school student's back-to-school "what I did this summer" essay, except that the character didn't actually do anything so it's more of a "what I saw other people do over Christmas vacation."
The increasing brutality of the bad things that happened around Clay seemed gratuitous given that there's almost zero payoff. The most Clay can manage is a tepid and fleeting "it seems wrong" response before walking out of the room. But recognition that the behavior is wrong doesn't spur him to any introspection or rejection of any part of the lifestyle or even to reject the friends engaging in the behavior. This left me feeling like the author was just laying on the brutality for nothing more than shock value. If there's no point to it (e.g. lesson learned, consequence, spur to action) then putting that imagery in the book is essentially just torture porn. The disturbing imagery served no plot goal because there was no plot. At the end of this book, I found the main character and my feelings toward him unchanged. It was an interesting character study, but not a story.