We have stayed here twice and really enjoyed it. If you have not been to Oahu before, you need to know that Ko Olina is to the west of Honolulu and sort of removed from a lot of the usual touristy type of places. The lagoons here are man made so the beaches are not as spectacular as many others on the island but all the other beaches are within driving distance and you can walk over to a lovely natural cove in the Ko Olina area.
The Marriott is a nice combination of laid back Hawaii with an upscale feel. If you have been to Maui, it has the same feel as many of the resorts in the Ka'anapali area. The pools are amazing, just look at trip advisor or yelp for some great everyday traveller photos or do a youtube walk through/tour of the pool areas to get a feel. I do like the pools at Aulani better but the Marriott ones are great too and they are open quite late (the Aulani ones close early-I hate that) There is always something fun happening if you like activities and events and 99% of them are included in the price you pay. One time we were walking through the lobby and there was a super long table just covered in loose orchid blossoms for you to make your own leis with. They have a little farmers market once a week where a couple of local people sell amazing fruits, veggies and baked goods. The popular Fia Fia Luau is held on one of the lawns at the Marriott so you can swim in one of the pools and watch it from a distance. They have outdoor movie nights on the same lawn with free popcorn and cotton candy. The list of things happening goes on and on. The rooms are very nice. The first time we stayed they were a little dated but a reno of all rooms has happened and they are up to date-light and bright with a subdued tropical theme. I feel that there are not enough dining options on the resort and the ones that are there are mediocre. I feel you need to leave the resort if you are going to out to eat all the time so you need a car. I personally would not stay here without a car and the parking per day is similar to Aulanis, something in the the $30-$40 a day range, just so you can budget for it or at the very least not have sticker shock. You can book this resort by renting through a time share owner on sites like Redweek and this makes it substantially less than direct through Marriott.
