I was born in North London but grew up in West Suffolk. The accent there was not as strong as East Suffolk and certainly not as strong as Norfolk. Despite having lived abroad for 40+ years I think I still have it. Not too posh, but not exactly Estuary or Cockney.
Here in Germany there are very many regional accents and no one is really looked down upon for having one. Many top politicians come from Bavaria or Swabia and have very distinctive accents. The big engineering companies (Daimler, Porsche, Siemens) are based in those areas, and the big chemical companies (BASF, Bayer, Boehringer, Hoechst) are based in areas such as the Palatinate and Hesse and are definitely not considered less worthy even if the CEO's have a regional accent.
I remember when I was learning German that it was thought that Hanover had the "correct" accent - that is the one that is taught to foreigners. You couldn't really reach German in a Bavariian or Fresian accent in foreign schools.
Having said that, many comedians cash in on their dialect and can say absolutely anything and have people rolling in the aisles, provided they are not in their home town, where they then have to tell real jokes, because the audience talks like them!
I think any voice with an accent or better still a dialect is really sexy in any language. Do they have surveys done in the UK where the various accents are graded by sexiness?