We were on the Veendam’s 18-day cruise to Hawaii that sailed on January 20, 2015 from San Diego and returned there on February 7th. The trip included stops at Maui (Lahaina), Honolulu (an overnight), Kauai, Kona, and Hilo plus a brief stop in Ensenada, Mexico on the way back.
Some pluses:
The weather was mostly sunny, and that includes the at sea days, which account for roughly 2/3 of the cruise. There were some rough waves heading out to Hawaii, but nothing that seemed to cause the passengers or the crew any problems. And the Pacific Ocean was remarkably calm on the sail back from Hawaii.
Extremely convenient for using the Neptune Lounge -- it is directly across from it.