While I do believe that Deborah Shelton played her role well, I was just never able to like the Mandy character. (And I am not a JR/Sue Ellen shipper, either). Mandy did not have much of a personality, and I felt like she had no real background, either. Basically, all we ever found out about her was that she was from Ohio (or was it Oklahoma?), and that she likes to work. How is that for vague? We never even saw her family. Basically, Mandy just seemed like a boring people-pleaser who was designed to almost always act polite and to be a sex toy for JR. They had absolutely nothing in common beyond the fact that they liked to have sex, and that does not make a relationship. JR needed someone like him. I believe that a big part of why his serious relationships (Sue Ellen, Mandy, Cally) all failed was because of a lack of similarity between them and and JR. The idea of the innocent, poor, ultra-polite good girl who becomes enchanted with Southfork and is basically a polar opposite to JR in most ways just wasn't working. Katherine had more in common with JR than all of the other women on Dallas put together, and he was a fool for not immediately trying to woo her after his first divorce back in season 5 (dvd).