In Ireland we have no trouble with any US accent, but we struggle with most of the English,Scottish and Welsh accents.And I spent many years working in England and most of the people found my north of Ireland accent impossible.
I have many relations in Pittsburgh and the accent sounded as easy to understand as any other part of the US I travelled through.
Wouldn`t it be bloody dull if we all spoke like Thatcher or Blair, two turn offs, here`s to all the incomprehensivels. Ard Mhacha.