I'm in the UK, and we left London for the rural outskirts of Bath in the South West six or seven years ago now. We don't have children, and we did it mostly for my mental health.
Occasionally I miss the intensity of the city. The ability to get any kind of food, amazing restaurants abound in London. I miss the diversity and multi-cultural makeup of the city.
For us, though, it's been the right decision... we're about 20 minutes from Bath, which is a UNESCO heritage site and a beautiful city.
And I'm only 90 minutes away from London on the train, for when I'm yearning for Selfridges or Harrods...