Speaking for myself and those I know in the Great Lakes area of the US, upon hearing a British accent, I will immediately classify it as Irish, Scottish, Welsh, or English. If the accent is "English," I will subclassify it if the accent is one of the better known ones, such as cockney or Liverpudlian. And, if the accent is that speaking-through-clenched-teeth accent of the upper crust, I might subconsciously ascribe class to the speaker. One thing I've learned in recent years is that the class distinctions in Britain are much more prominent than they are around here, and I get the idea that the accent says a lot more about one's station in life in Britain than it does in Michigan.
The single biggest distinction I can think of regarding speech patterns in this area is the use of the double negative. When middle and upper class Michiganians hear, "I ain't got no ...," the status of the speaker is immediately fixed.
