Tena,
I agree that grading rubrics are helpful because they streamline the grading process. One problem I have found is that our rubrics are embedded in the course and we cannot change them. Many of the categories overlap, so when a studnet forgets part of an assignment, if I follow the rubric closely, I would be deducting points in two areas. If I don't follow it closely, why have them? Either way, the breakdown is confusing to students. I think that in order to be effective, they must be well-developed.