P.S. 172 Beacon School of Excellence vs P.S. 321 William Penn Compare P.S. 172 Beacon School of Excellence (15K172) and P.S. 321 William Penn (15K321) side-by-side: test scores, climate ratings, demographics, programs, and more. P.S. 172 Beacon School of Excellence (15K172) — District 15P.S. 321 William Penn (15K321) — District 15