Bingley, I would prefer what you describe as the ordinary, unobtrusive broadcast voice. What purpose would it serve to inject a local accent into the words especially if, the speaker himself does not employ such an accent when he converses in English?

I also agree heartily with Bean's comment on subtitles. It is so much more pleasurable to listen to the languages themselves and use subtitles for comprehension. I have often thought this very same thought, whilst watching live telecasts of UN debates. Most of the speeches have a grating english voice-over which follows the actual words after a brief time lag and the effect can be jarring at times.