It sounds like the English majors have had their poke at the story, and made some interesting points. As for me, I don't know English, but I know what I like.
I liked this story because the characters are compelling. They're not stereotypes, they're not just metaphors; to me they feel like real people, with real concerns, real emotions, and a real story. It's true Duncan buys Eleanor to use as bait, and uses her to kill unicorns... but he takes care of her, watches out for her, seems to respect her in a way, and it feels sincere when he says she's earned her freedom. Is he a bad man who's had a change of heart? Is he a good man with a terrible past, or an obsessive agenda? It's hard to say, but we see his turmoil, some of his hopes and doubts, and he feels very real as he grows through this story.
Eleanor gets less screen time than Duncan, but she feels real too. She's traumatized by her past, but she comes to accept her fate, pick up some skills, and realize that she has a hand in writing her future. If the story had been told from more of a third-person perspective, she could easily be the main character. What awaits her after this narrative - is a happy ending possible, with or without Duncan? I can't say, but she certainly has hopes and dreams, and we want to see how she goes about working towards them.
I also wanted to say that the narration for this episode was incredible! I can't believe more people didn't mention this. A flat reading could have made this story unpalatable given its content, but John Trevillian gave the characters life, breath, emotion, and depth. I could hear Duncan's outward callousness, but inward doubts and fears. I could hear his panic and feel his heart pound when he was desperate to see if Eleanor was wounded. A good narrator helps the story flow and helps you suspend disbelief so you can identify with the characters. A great one makes them come alive and makes them feel real!