We are going the week after yours and are so excited! We love Kapolei and Ko Olina. This is our 4th time in Oahu and 3rd time with kids. We usually stay at the Marriott since we have a timeshare there, but have recently became
DVC member. Can't wait to experience Aulani in the future. Our audience is a little different than yours (girls 8,5, 8 months), but will try to remember what we did when we went as a couple in our early 20s.
Attractions: Pearl Harbor was a very humbling and unforgettable experience. We actually just rode the bus from Waikiki if I remember correctly. If you have a car, I think you can just go get tickets early in the morning? We have not gone in a long time so not sure if it has changed. Kualoa Ranch movie set ATV was fun, according to DH. He went with a friend while I went with the girls (at that time 4, 1 1/2) on a movie set bus tour. They loved their ATV experience but I can tell you, DO NOT do the bus tour! Luau is definitely a must do if it will be a trip of a lifetime. We have been to 4 luaus: PCC, Germaine's, Paradise Cove, and Marriott's. PCC was a long day. Can't remember much about Germaine's. I thought the activities were the best at Paradise Cove, but food was best at Marriott's. Definitely, do the Diamond Head hike. Gorgeous! There is also a hike to a waterfall that I have not done, but heard it was nice too. Don't know if the boys have significant others, but the swap meet was a really fun place to buy souvenirs for cheap. Also maybe fun for you for same and also had reasonably-priced cooking items (oils, butters, jellies, etc). I have not been able to find those elsewhere. Hanauma Bay was awesome for snorkeling. I know there are probably better places but for first time snorkelers, I remember it was pretty fun! DH also liked taking a surfing lesson in Waikiki. One of the best memories I have of Oahu was renting a convertible and driving around the island with DH for a day. It was so much fun and so wonderful to be able to take in the beauty of Hawaii like that.
Food: This is what we have planned for this trip... Helena's: it is in Honolulu and super busy but OMG, food is delicious. Great lau lau and fried butterfish collar. Great haupia too! We usually pick up to go on the way from airport to hotel since the restaurant is usually packed. We also pick up on the way to airport as our last meal on the island. Not sure if you are adventurous, but must try if you are. This time I am going to try the squid luau there. Leonard's: there is one in Waikele shopping center which is closest to Kapolei. Great thing is it is on the way to North Shore, Waikiki, and everywhere! We usually stop by for breakfast! I went on 3 trips to Oahu and did not try malasadas until our last trip. What were we thinking?!!! Definite DO NOT MISS. So yummy, especially the haupia one. Dole Plantation: this is my must do every trip for my Dole Whip soft serve fix. My girls still enjoy the train ride and my 8 year old wants to try the maze if it doesn't rain this year. They also sell the ornaments that you can personalize there. I let the girls choose one for their yearly ornament when we go there. Shrimp truck: I don't know if there is a huge difference in taste. I feel like they all taste the same honestly. When I went with DH 12 years ago, there was this truck that had a little shrimp pond and you can catch your own jumping shrimp! Have been trying to look for that one for years since the girls would like it, but have not been successful. Duke's: very nice place to eat. Used to be a place I look forward to, but too many fearless birds. I have this very intense dislike for birds and there were just way too many roaming around last time, so we will not go again. We are also going to try this time a hot pot place since we don't have too many of those in our area, Sushi Bay in Kapolei, Fresh Catch, Mike & Billz Fire Grillz and a food court at this Japanese store at Ala Moana. For breakfast, we may try My Cafe and maybe the character breakfast at Aulani.
I am not very helpful with the activities at Aulani since we have not stayed there yet. However, their lazy river definitely looks really nice. Hope you have a lot of fun during your trip and maybe you can share some of your experiences at Aulani with me when you get back!