I responded to your similar question over on the DCL Board here, but for the convenience of others following this thread I'll repeat my comments here too.
We did a combination Aulani and inter-island cruise in February of this year. We spent 7 days at Aulani followed by a 7-night island cruise on NCL's Pride of America. If I were doing it again I might reverse the order of the two. In the end we found that while we enjoyed seeing the other islands, it was Aulani that we loved the best.
This is going to sound terrible, but frankly once you've seen 2-3 of the islands they kind of blur together. I really don't mean that to sound bad, they really are all gorgeous, with lush scenery and beautiful beaches. I just don't know how many times you can shop at similar shops or visit similar beaches or marvel at similar mountainscapes. Again, yes we did enjoy the islands. I just wanted to temper your expectations.
As far as the ship goes, we've had better cruises. The level of crew interaction on board was spotty. Some crew were wonderful. Others were just there earning a paycheck. Dining on board was also a bit of a disappointment. We sailed in concierge suites (three different suites in our travel party) which gets you a very nice room and a personal "butler". An example of the un-evenness of the service was that our butler was fine (not exceptional but fine), one of the other butlers acted like he was being put out whenever asked to do something, while the third one went out of his way to please his passengers.
Our experience at Aulani was uniformly good. This was our second visit to Aulani, having spent 4-nights there in 2014 as well. The CM's there are all very well trained and genuinely friendly. We enjoyed just spending time enjoying the lush grounds but also made time to see the other parts of Oahu. Pearl Harbor is a must. We spent about 4-hours there, hitting it about 9 am. Before you go, hit their website and purchase your timed tickets for the Arizona memorial. Then plan your visit to get there at least an hour ahead of time so you can look at the exhibits before you get on the boat. We then spent a bit more time looking at the various artifacts before leaving. We did not do the tours of the various ships but you might be interested in that too.
Other things we did on Oahu were to go into Waikiki just for the "tourist" experience there and to eat in a couple of restaurants. One real surprise was the Pineapple Room by Alan Wong, which is found in a Macy's store of all places. We drove up to Diamond Head and then further along that stretch of coast taking in some beautiful sights. On another day we drove up to the North Shore, stopping at the Dole Plantation along the way just to shop for about a half-hour. Some folks like to take the tour at the Dole plantation, which will take longer. Once at the North Shore we pretty much just drove along the coast road and did stop at one of the multitude of shrimp trucks. Its kind of a must-do experience as is getting shaved ice.
Another day we drove over to Kailua for more shopping and site seeing. The drive over there is really spectacular as you go through a tunnel in the mountains and come out the other side. Beautiful scenery all around.
I adore 40's and 50's (and early 60's) kitsch.
