inception said: "There may be regional variations, but those variations are often only noticeable to people from those regions. I did a bicycle tour in Chicago with a large group from the UK. When I said I was from Canada, they all said, "But your accent sounds like you're American!" I was like, " Not rilly, mAby Uh soun a bit Wes Coas, mAby a bit Culifornian, buh wence Uh sA tha werd ABOOT evrywhen here wyll knuh Uh'm from CAnuduh, eh"
I'm not sure that is true. I agree Canada is tricky (btw, do u say ABOOT? I usually here ABOAT) but I do not think most North Americans lack an awareness of the significant differences between, at least, posh, cockney, yorkshire, scouse (since 1964), brummie (since Ozzy), and Scottish. That said, I don't think Sweeney demands a particular accent in American productions.