With so much history covering over 1400 years, there's no way a museum can do justice to this place. The talking guide sets are worth every penny (they're free!), and once you've got used to the slightly Listen-With-Mother tone of some of the commentary, they're very informative and comprehensive. They also give you a feel for what it must have been like to live during the various periods described.
Do also try the teashop. First-rate tea and scones and tables overlooking the bay.