You sound very like us, Elisabet31 - we lived in north London for years in a tiny zone 2 flat, before we moved out when my son was a baby, after a messy set of circumstances. DH commuted Leicester-London for a while when I was on mat leave, but it really wasn't practical longterm, and we'd grown out of our flat, so we moved here, and I'm now working locally. We're planning to stay for another year and then try to find a city where we can both work.
Unfortunately, we really can't afford to move back to London, though I do still miss lots of things about it - as well as the obvious cultural things (I'm passionate for theatre, classical music, esp opera), as you say it's the sheer variety of people. We had (still have!) friends from all over the world, who did all kinds of things in life and often worked in the arts and lived hand to mouth - and I'm a bit beiged out by the lack of variety of people I meet here, nice though many of them are.
Preponderance of SAHMs who have only ever lived locally, surrounded by extended family, and seem very invested in their homes, children and village gossip. I must admit to finding it a bit depressing that I'm considered so strange - foreign, 'accent', speaks other languages, leftwing, unconventional job, only one child and no plans for more, etc etc - and it has limited friendships, because we literally have no common ground, even when people mean very well, and I'm also making a big effort.
Obviously, I suspect Market H may be a bit more various!
It comes down, I suspect, to what is important to you, and what you want from the move. We have ten times more space, peace and quiet, a lovely garden, beautiful countryside, abundant wildlife, a crime-free environment - but the world outside, especially socially and culturally, is simply nowhere near as interesting as our London life, and I feel very isolated.