We took the Making of Harry Potter tour and the Downton Abbey (including Cotswolds, Village and Highclere Castle)/Oxford tours. Both were very good but there are several things that would have improved the HP experience: other tours apparently showed portions of one of the movies on the bus. That would have added to the experience and shortened the feeling of the drive. Tell people in advance that if they pass by the butter beer place, they won't be able to go back (or make Warner Brothers change that) and third, tell people they can get alot ot the HP stuff in Oxford, with a lot of selection, shorter lines, and possibly better deals.