I'm completely in love with this book. 
 First of all, I think that Fowles totally stuck to his first intention of keeping the meaning of "novel", to create something new. In fact, he did. 
 The idea is nothing similar to anything I have ever read before. When I was first told about the plot of the story, I thought it was going to be boring or distressing, anguishing (and it is, but it is so much more too). 
 The characters Fowles presents are the life of the book. Not the events themselves, but the characters. I think it is incredible the way he sticks to the inner temper of each of them; how he shows the sick mind of Clegg, how it works, how he does not care, how he justifies himself... if someone had told me it was a real account of a real event, I would have believed that person. On the other hand, I love the way Miranda evolves all through the book. And the realism of her thoughts. How she wants to escape, how she hates Clegg and how she needs him to avoid madness at the same time. How she reflects on a lot of different issues (culture, morals, war, love, sex...) and the way she reflects Fowles' ideology, especially that of the Few and the Many. 
 To sum up, I love all the psychological side of the novel. 
 Another issue I really enjoyed was the paragraphs about art. How she tries to teach him, how she talks about painting and life and creation. G.P.'s ideas and her attempts to escape from her reality through painting (she paints a lot of skies), drawing (even her "Caliban" gets draw by her), copying. She wants to escape and paint a lot of different faces, strange faces. She wants to live to grow and paint better, transmit better, create better. 
 Finally, I liked the book so much because of its language. Its fluidity, its colloquialisms, its simplcity. Fowles uses the words he needs and no more. No three lines to talk about a blue sky, no twenty words to describe anger. The book is like talking, like thinking. No difficult words, no long dialogues without a purpose. 
 To sum up, the mere idea of the plot, the characters, the art and the language made of this book, to me, one of the best ones I have ever read. I am completely in love with the whole of it and therefore, with John Fowles in some way.