The S&T program is largely a school within a school. The S&T kids take specific S&T sections of math, science and engineering and then they are automatically in honors English and social studies. Freshman year they move as a cohort for their core courses so it is more like middle school. Any electives and lunch are mixed with the student body (Choir, band, languages, health etc.)
My child is a motivated student by nature but I know other kids who have done well at the school who aren't.
Many PGCPs high schools are around ~2400 students. Bowie has a second campus just for 9th graders.