For most performance majors, the teacher is a primary factor in choosing a school. Artist teachers can often facilitate preparation for the profession. The student must be prepared for periods of absence when the artist is on tour, perhaps having lessons with an assistant. One wants to also be aware of politics, personalities, and psychological approaches. It is also useful to find out successful graduates.
Size can influence the experience.
Some students are overwhelmed in a large school while others are energized. From a skill development perspective, it should be noted that pianists need good string players for sonatas and chamber music. Violinists need violists, cellists and bassists for chamber music and orchestral experience AND winds, brass and percussion for full symphonic orchestral experience. A large comprehensive music school can usually provide this kind of experience. On the other hand, some students have found their most appropriate teacher in a smaller school and have been able to achieve the above experiences within the community.