I absolutely loved Norrell and Strange, and raced through it when it first came out. I thought that it was a really fantastic re-imagining of Victorian England and the Napoleonic Wars and that Clarke wove in some alternative history (the Raven King, the separate kingdom of the north etc etc) very well indeed. Beautifully written and realised. With regard to Harry Potter, I think that although the plots and the storylines were definitely, undeniably derivative, JK Rowling's strength is in her portrayal of the conversations and interactions with characters. I've read many books that have great, creative plots but where the author has really fallen down on creating believable characters - they are wooden, their conversations aren't fluid nor believable and so on. Whilst Rowling's literary talent isn't nearly as great as some would have you believe, I think that she does create good characters.