If you start this book and immediately think "Is she a real person?", Don't worry, I thought the same thing and i doubt I'm alone in that. (Hint: she's fictional)
This book was explosive- full of Hollywood scandals, romances and affairs. And despite the title, this book is LGBT heavy. You've got gay, lesbian, and bi characters and it (importantly I think) covers the issue of bi-phobia/bi-erasure.
Reading this feels like a blissful escape into someone else's dramatic life and I'm sure I'll be re-reading it before long.