We are doing an Ocean Princess repositioning cruise, San Juan - Vancouver, 22 days, 04/29/0. This is actually 3 cruises back-to-back-to-back: a 12-day Panama Canal (SJ-Acapulco), 7-day Mexican Riviera (Acapulco-LA), and 3-day Coastal (LA-Vanouver).
As I understand it the menus and the entertainment will be repeated. However, I am not worried. On our Alaska cruise (Sun P. 05/15/00) there were a few shows we missed, and there were many things on the menus I could not try in 7 days - there are four different entres every night, plus the four 'always availables'; also, many of these were so good that I would probably order them on the next cycle. You always have alternative dining as well. Assuming you only order one entre every night, it would take months of back-to-backs before you were forced to eat something twice if you exausted all the possibilities in the dining room and the alternatives.