as said you will be well positioned for Edinburgh or Newcastle. In general I'd advise getting the train, that A1 is not the best of roads, mostly single carriageway from Berwick to Newcastle apart from a a few bits, and mostly single from Berwick to Dunbar, so its not a fast road. Its ridiculous that a main road from Scotland's capital to a major English town is like this, but there has never been the political will to dual it all. What foreigners make of it I don't know, stuck behind tractors for miles.