I served with a guy from Glasgow, took three days before I understood a word he said :)
Yet I've had friends from Aberdeen who I had no trouble understanding.
Different accent every ten minute drive, in Britain!
Discussion
That's part of the charm, of Britain.
Dated a Scottish guy, but he had an Oxford dialect, which isn't nearly as charming. Definitely always go full burr.
I also love how Dubliners sound like they're singing, when they speak.