There's many reasons we did. Chiefly, it's far far cheaper. But also, it's calmer and quieter and just a nicer way to live. What we didn't expect to see, which we are absolutely delighted about, is how different childhood seems to get lived in a much smaller city. There have been roving bands of children on bikes all summer getting into who knows what kind of awesome mischief.
We go on completely random drives 3 or 4 times a week, just wandering the city to get to know it better (and get the youngest to nap) and we see kids and young teens all over the place without parents.
Anecdotally of course, but I wonder if smaller cities/towns lend themselves to a far more trusting, free, safe environment to grow up. When I picture letting my boys, when older, go out on their own, I'm thinking about the difference between here and where I used to live. The scariest street has 4 lanes total and is a 50km/h. There's no rapid transit to smoosh them. There's a wonderful central park just one traffic light away. Literally everything in the city is a bike ride away.