Well, so are we. We insisted that it be done by colleagues, not department heads or Deans, but we kept it quite light. The best final policy would rather clearly indicate that for the vast majority of faculty, review occurs every six years. Peer evaluation of teaching is essential. Let us devote resources to visiting each other's classes and offering feedback on teaching.
Students have many areas of expertise, and can hold strong opinions.
But it is teachers who are more expert on teaching, not students. The fact that alumni often look back on their time in the University and remember fondly the times when they were pushed and pushed to work hard, yet at the time they were students they complained loudly about workload, is enough for me to conclude that evaluation of teaching requires some distance, not the intense, personal involvement that a student has. PTR must be collaborative and cooperative, not confrontational. It is counterproductive. You catch more flies with honey then vinegar.