I listened to the audio book version and loved it. Yes, there are lots of characters, and I had to pay close attention to the reader to sort them all out. I found myself liking the foul-mouthed Crystal and hoping she would make it and be able to find a way out of her horrible life just as her rowing coach, Barry Fairbrother, had done. I think Rowling's characters' development was well done; as you progress, you see their personalities take shape. I highly recommend this book.
This was not Harry Potter, so don't expect it to be. This is the story of the political maneuvering in a small British town. It speaks to greed and vice and ambition, family dynamics, and the social welfare system. There were few people to cheer for, as each character was written frankly, with all their human flaws exposed.