Reply #1: Not sure about exchange rates

[tjwmason]

In some cases it might be better to use credit cards.

Small note about Scottish money, up there they have slightly different notes. In addition to the usual Bank of England issued £5, £10, £20 and £50, there are also the same issued by the Bank of Scotland, the Royal Bank of Scotland, and the Clydesdale Bank - plus the R.B.S. issues a £1, though these are pretty rare. Changing these back into dollars after returning might be a bit of trouble; and they might look odd at first.