I'm also like to know ahead before I make a quilt. For two years I observed everyone's progress on the Bonnie Hunter mystery quilts. It was fun to watch. I took a leap of faith the following year after Bonnie posted the colors. The best part was the camaraderie and learning new skills. I did like the quilt and don't regret doing the mystery.
But.....I also learned that for me, scrappy is too busy for Bonnie's patterns. I would have been happier with one constant fabric for each color. I will still follow the mystery but will download the directions. I won't make a commitment to do the quilt until after seeing the finished quilt.