Dick Van Dyke spoke with an accent that you only hear in Disney films. Nobody over here uses the term 'guvnor,' nor pronounces lovely 'luvverly
Funny - My Fair Lady also uses "loverly" and "guvna". I wonder if that is why we assume the Brits use it? I guess that is something just from that era of movie making? Mary Poppins and My Fair Lady were both released in 1964 I think.
I think actors speak "southern" horribly. I cringe when I hear them in some movies.
I tend to not notice accents at all unless they are unusual or really bad. I mean to say - I hear it and recognize it as British, Australian, etc... - no big deal. Unless the person is butchering the heck out of it for some reason. If it seems assumed - then it is usually better just to speak with your regular voice. It seems to be more distracting than anything.
Just as an aside - I was in New York one time and the cab driver asked me if I was from England! Totally cracked me up. I am quite southern in my drawl. Maybe not to the extent of some of my family but still - noticeably so.
Anyway - back to the subject at hand. Izzy - was Renee' Zellweger's (however you spell her name) accent good in Bridget Jone's Diary? What about Gwynneth Paltrow in Emma? Just curious. Though that is the opposite.
I think Robert Pattinson does a lovely American voice. Sans Brit overtones.
Of course it wouldn't matter if he didn't. I just think he is pretty.