I liked Gone Girl, and I'm half way through Dark Places and so far think it's brilliant. However, Sharp Objects is a classic shock value novel. It's very disappointing. I felt as if this was the author trying to show she could write dark and edgy; and what I read was a series of cliches, horrendous description and metaphor taken too far.
The main character is unlikable. In fact, everyone in this book is a shock character and unlikable. It's therefore hard to really connect with the world. It's unreal and out of a low budget gore film. The self harm, if I'm honest, is written in an almost offensive manner; I say this working for a mental health organisation (although I am by no means a specialist). She took a concept too far, and seemed again to use it for shock value.
The story boarders on offensive at times, which is why I don't rate it highly. The writing is wonderful, and you can see her growing as a writer in her two later novels. However this one, I would not recommend.