Yes to both of you! I've always hated the question, "Do your kids go to a good school?" Because no, on paper this is not a good school. It serves kids of a lot of different abilities and backgrounds, so the test scores don't come out to a nice average or anything. But the personal connection is priceless. The elementary STEM teacher, who was my daughter's second grade classroom teacher, got her early access to all kinds of opportunities, like a STEM field trip, and the fifth grade robotics team. The middle school honors math teacher actively fought for the privilege of having my kids in his classes. The middle school english teacher pushed my son to submit his essay to a contest he subsequently won, and found a leadership position she thought he should apply for. The elementary garden teacher STILL seeks out opportunities for my daughter -- for example, he has arranged for her to enroll in a residential workshop next summer that's usually only open to postsecondary culinary students, and he's even figured out a chaperone for her. I can't imagine being anywhere else.
I definitely agree that supportive teachers plus students who make it obvious when they are not in a good academic match can make acceleration an easier sell. The flip side also seems to be true.
Supportive teachers who can be flexible in the classroom, combined with kids who are willing to seek out their own challenge, combined with extracurricular enrichment opportunities, make acceleration seem less necessary! Which is probably why mine have not "needed" to be anywhere but in their age-grade classrooms...until now.