This is coming from an outside perspective - so bear with me. I lived in Wandsworth/Merton area. and when I was younger I used to hear so many people talk about Sutton and Croydon (and areas around there) and how bad it is. What's wrong with it? As far as I've known, I've pointed out differences:
Sutton
Primary aged kids, families with younger children, Christians, big open spaces, and feels like a village.
Croydon:
Younger people, young adults, big nightlife, lots of shops, chavvy, secondary aged kids and lots of cultures.