I recommend FanStory. I tried other sites prior to finding FanStory and they were not what I was looking for. FanStory appealed to me because it caters to the more serious writer. The feedback I have received at FanStory has primarily been detailed and thoughtful. I get feedback for chapters in my book as I write them. The people writing reviews are other writers that seem to be very interested in helping me. The reviews are helpful and because of these reviews I find that my book is improving and I'm improving as a writer as well. FanStory was the site I was looking for. I recommend it to any writer looking to improve.