In reading the self evaluations, both Mr. Geeky and I have noted two things. One, the students admit to being terrified at first because they had always been given specific topics and a specific formula to write to. Two, they admit that they learned a lot from this initial fear and worked through it and basically discovered their own voice and their own passions. This reminds me quite a bit of Peter Elbow's work. I do plan to include some of his ideas.
We've noted a lot of other things as well, but these two themes keep recurring.