We were in the same situation 18months ago. We were considering Lewes as I didnt want to move out to be in the commuter belt, personal preference. I am a city girl but i know i can learn to love to live in the countryside.
BUT we decided to stay in battersea for a few reasons, which meant a compromise on the size of the house/garden (the house i viewed in lewes for less money: 5/6 bedrooms, detached, huge garden, basement, big kirchen, 2 reception rooms, etc!!!):
1. When you are out of london, we found that you are in England... Well being both foreigners we didnt want to raise our children in england; and it makes travelling abroad easier;
2. My husband would have had a longer commute which meant not able to see the children in the morning when they wake up (7am) before he leaves for work (7.20) and for him these 20min are paramount;
3. Having been myself in london for 7yrs, i have now a very good social life with people and network and friends that i have built over the yrs and who almost all are in london. I absolutely love my life here and i didnt want to start again... Selfish i know but my sanity is important
4. We absolutely cannot stand having to drive for fresh croissants and bagels (children favourite) at the we, when we have a fab bakery accross the main road. We do not have a car and dont miss it.
My advice is make s list of what is important for you, prioritise and a list of things you are happy to compromise on. And see which area answers most of your criterias.
Good luck, tough one. Sx