Re: Upper calss first
I can only comment on the Sheffield and Cardiff exchanges:
Ranmoor: Solid middle class. Some traditional working class and student occupation.
Beauchief: Solid middle class
Llanisien: Mainly solid middle class. One large ex-public housing estate
Llanedeyrn: Some very exclusive bits, but mainly a massive, and quite poor estate
Of course, I'm only guessing at the actually boundaries of the BT areas and assuming they coincide with what local people people refer to when using the area names.