I would like to recomend an excellent book for those who love Chopin: "Chopin pianist and teacher as seen by his pupils", by Jean-Jacques Eigeldinger. In it, we can find a collection of documents, including the statements of Chopin's own students in their diaries or letters, personal accounts of Chopin's playing as experienced by his contemporaries: composers(such as Mendelssohn, Liszt),pianists(like the interesting statement of Hallé: "...I went to dine with Baron Eichtal, where I was very cordially treated, and where I heard -CHOPIN. That was beyond all words. The few senses I had quite left me. I could have jumped into the Seine. Everything I hear now seems so insignificant, that I would rather not hear it at all. Chopin! He's no man, he's an angel, a god...", pupils and friends, as well as his own pupils' annotated scores (including the entire score of Nocturne op.9 n.2!). As you see, this is a very serious book on this subject, and the explanations and critics of Eigeldinger are extremely interesting. You should read it!