First, welcome to Cruise-Chet! None of the American flagged vessels get good reviews but they have been getting better reports than in the past. Service in the dining rooms seems to be the main issue. It's just terribly disorganized as much of the staff is trainees. They have a huge turnover on these ships. Overall I'm certain you'll enjoy seeing the islands and won't regret the cruise. Just lower your expectations a little from what you have experienced on other cruises. A week + in Hawaii and multiple islands is worht a little disorganization.
Would love to hear of your experience when you return.