Heuristic on Teachers 

Not that one has a choice, but if you're below college aged, opt for older teachers but once in college and grad school opt for younger teachers. Why?

Old teachers are more "stuck in their ways" and for younger kids, those ways are good. They teach classics and basics and foundational elements with tried and true methodology. 

Younger teachers are not so much and more connected to the way things are now. And that will help you transition out into the workforce as one is preparing to do when in college and grad school.

Caveat: I don't just mean in age, but also soul. So an old teacher can feel "young" and those folks would be good college/grad school professors. Likewise, a young teacher could feel "old school" and they'd be good in elementary school.

No proof, just my instinct.