We have just returned from a Southeast Asia cruise on the Diamond Princess.
The cruise was very good overall, but unfortunately we did not get to see Shanghai due to bad weather. The captain only told us two hours beforehand at approximately 6am that we were unable to dock at Shanghai as the port was closed due to bad weather. We therefore remained at sea for three days and missed a very popular port that we were all looking forward to visit. To add insult to our disappointment, in the captain's final speech before disembarkation he mentioned our cruise "... had beaten the record of eating the most food on board". Perhaps missing a port on our itinerary and three consecutive days at sea drove us to comfort eating!
I agree with other passengers reviews regarding the many problems on the Diamond Princess e.g. the ships mechanical vibration, the $25 per head dining surcharge, the expensive shore excursions, the mediocre entertainment and food to name a few. Furthermore, the gym was small for the size of ship and the classes almost non-existent e.g. the spinning only lasted for a couple of classes until the instructor disembarked at Hong Kong and was never replaced. The Skywalkers Nightclub was a waste of time and could do with an injection of someone like Jamie from the cruise staff. Diamond Princess has poor sanitation control and does not do enough to stop passengers bringing bacteria onto the ship. Most of the passengers had bad coughs by the end of the cruise.
Don't bother complaining to the Princess Cruises customer services as they will only quote you their t&c's and then hope you will travel with them again.