Also: the British show took place in Manchester, and I honestly believe that most Americans would have difficulty penetrating the accents.
You know, I met a girl from Manchester at my University recently, and I had no trouble understanding her. I did, however, have absolutely no
idea where in Britain she was from -- I could tell it was a British accent, but it didn't sound like any I'd heard before. It wasn't quite Scottish, it didn't quite sound like the Northern accent Christopher Eccleston has, it certainly didn't sound Liverpoolian or Cockney or Estuary or RP. I finally broke down and asked her.