I've heard that the mystery novel isn't bad.
On the other hand, I finally read The Casual Vacancy and have to disagree with those who liked it. I thought it was a tiresome book full of gratuitous efforts to shock us and prove that Rowling can write adult fiction - provided "adult" is equivalent to 100% dysfunctional families, lots of swearing and constant references to male/ female sex organs. (when an author's casual description of a fat man opening his shop includes a mention of his penis, she is trying way too hard to overcome her image as a children's book writer.)
To be perfectly honest, I read the first quarter of the book, then dipped ahead to see if the rest was just as full of unpleasant, nasty, gossipy characters. Given that the pages I randomly picked included a rape, self-mutilation, heroin use (these 3 events involving 3 different characters) and lots of ugly and juvenile behavior by the average citizens of this town, I checked some reviews to see if there was any point to continuing. They seemed to be equally divided between people who hated it (several mentioned wanting a shower or being depressed afterward) and people who loved it. So I decided I fell into the former category and didn't waste my time with the rest.
Luckily, I only spent a dollar on it.