I'll stick in a comment from my wife, as she's not a member in her own right:
My wife is a Johnston, & fiercely proud of the fact. She wears the tartan & clan regalia with pride, & woe betide anyone who belittles either! However, when asked if she's Scottish, she replies in the following order: "I'm an Ulsterwoman, then I'm an Irishwoman, then I'm of Scots descent". Her family migrated to Ireland during "the 42", & her belief is that 400 years in Ireland makes her Irish. For what it's worth, her lot are outside the normal migration pattern, as she's a Caskabene (sp?) Johnston rather than an Annandale, thus a highlander.