Also, I think production has gotten stricter and stricter over the years with what the contestants can do in their spare time. I think Katie partly stopped after Cutthroat because it just became too restrictive, if I recall correctly.
I feel like Theresa should in theory be a great contestant for The Challenge, but she has always rubbed me the wrong way and annoyed the everliving shit out of me. Her only elimination wins that I can recall were against a checked out Camilla in Free Agents and against Nany (who isn't good at eliminations herself) in Battle of the Exes II. I feel like she buys into her own hype a lot.
I was generally a Veronica fan, but Inferno II is the one season where I couldn't stand her. Even when she was being a mean girl, I understood where she was coming from on her other seasons, but it just seemed to make no sense to torment Tonya.