Hello from Lyle and Linda. We did this trip back in March of this year and we rated it the BEST cruise ever and one which we would repeat. One tip - don't book H.A's shore excusions.....too expensive and you can get ones similar or better on shore for at least half the cost. The snorkling was also THE best and makes the water in and around Hawaii for example, look cloudy. Even if one doesn't wait to actually snorkle one can wade through the shallows and almost touch the fish (please don't!) but the water is sooooo clear its amazing. We swum with/near reef sharks (they don't eat humans), manterays and of course fish and turtles.
The Rotterdam was also very good. Sometimes the dining room service was slow but we know from experience that this can simply be new staff in the kitchen or for that matter a new waiter.
You will love it I am sure.
Thanks for the tip, twovictorians!