I've heard great things about Christiane and it doesn't suprise me that she was great.
As for my take on Amy- she just didn't pull it off. She played Hope as too over the top and took the character in a direction I'm still not sure worked. She made Hope seem easy and cartoonish. Granted all of the characters in the show weren't exactly realistic but the fact that they played them so seriously and so real was what made them so good. For me, the way Jennifer Laura Thompson played her, with almost innocence about her was the way Hope was meant to be. One of the times I went I saw Rachel Coloff go on as Hope and although she didn't play her the same as Jen did, she did a fantastic job. With Amy, she was simply annoying. Not to mention my biggest annoyance with her (and likewise with Luther Creek) was the kiss at the end of Follow Your Heart, when done with those two was over the top and obnoxious. I'm not a huge Amy fan- I enjoy her voice on the recording of tick, tick, boom and I thought she was a great dancer in Kiss Me Kate when I saw her in that (although acting to me was only mediocre) but in Urinetown I felt her performance was horrible.
And hang on, when did you win the discus?