Kirstey raises a good point about the triangle around Bewl Water as there is nobody really to talk to as far as I know. There is Shoreham at the bottom end, Southend or Manston if you are in that area but no-one else.
I generally use London FIS for the Chatham and London ASR service and would prefer to talk to someone rather than nobody at all provided I am outside an ATC area.
Presumably this is a good idea? Does anyone have a better solution?