re: Have you moved from a larger to city to a small town / countryside? How was it?

I've never lived in an urban area.
I lived in Dekalb and Gwinnett Counties (about 1M people in each).

The traffic headaches were awful (expect to wait 3 lights before you can make a left hand turn at any intersection).
During the housing boom (2005-2006), there were drug houses popping up in subdivisions.

I now live in a county with under 30,000 people. 1 high school.

The first thing we noticed was that fast food restaurants are pleasant.
Convenience stores are aplenty.

We have been in the school system for 14 years. I recognize that the high school only offers 2 foreign languages (Spanish and ASL) where other schools could have as many as 6. And that could be an example for limits on AP offerings.

But the actual student experience is up to the actual student (more than the school). Low performing schools can have perfect scores on SATs and send kids to the naval academy just like private schools. And conversely, burnouts can happen at both schools as well.

Our school district partners with multiple colleges (University of North Georgia, Young Harris College, and Lanier Tech College) to offer their entire suite of college classes to high schoolers. It isn't the AP that UGA or GT prefers, but a vast number of students are entering college as sophomores.

We are very active in sports and academic clubs.
But we are not active in churches or social clubs. We are more tied to family in the area than our direct neighbors.
But that is our choice.
I firmly believe that we would feel the small town community if we were involved in one of the local churches.
Those (and rotary) are the social clubs of small towns.