private schools in Boston area: Sage School, BB&N, Park Street School

<p>I am interested in getting feedback on private K-8 or K-12 schools in the Boston area, and what are good schools for students who love learning and are ready for advanced learning opportunities. Particularly interested in Sage School (for gifted students) in Foxboro, BB&N (lower school), and Park Street School (downtown Boston). </p>

<p>Thanks in advance!</p>