I read the original "Story of O" ; the edition with a foreword by Sylvia Day, not the book pictured here. There were no covers of the original. If you're looking for entertainment, I would not recommend this book. There are no details as to how the physical activities affect O other than occasional references to 'burning in her loins'. There really is no story line, or character development. It reads much like a diary. However, if you are interested in the psychology of the submissive and a detailed analysis of her thought processes, then you may enjoy it.
What do You think about Return To The Chateau (1995)?