I'm neither a FH Lifer nor a 10 minute wonder, but sadly Ian is correct when he says that FH has gone down compared to twenty years ago. I lived in FH from the mid 1950's until around 1970 and it was an extremely nice place to live.
However, having grown up in SE23 I've stayed in touch and for all the changes I've seen I still think it is a cut above the rest of the SE postcodes.