We've been to this resort at least 5 times since building began in 2003, so we've seen it grow into a really special resort. Definitely a family-oriented place, if you don't have kids but still want to experience the west side of Oahu you can check out the JW Marriott Ko Olina, or the vacation villas in the middle of the two properties (or you can find private rentals of the condos on the golf course). A 3/4-mile paved path along the ocean connects all the Ko Olina hotels, and there are 4 quiet swimming lagoons along the path. The location is gorgeous, you can't beat the views and serenity.
Ko Olina has the most reliable weather in Oahu -- in December we typically get sun and breezes every day while it can rain on the rest of the island. West shore is a very relaxed, quiet part of the island. There isn't any nightlife at these resorts other than a few bars open with some live music, or the luaus. If you want a party atmosphere you need to go into Waikiki. They've built a Costco up the road in Kaploei, a 5-10 minute drive. There is a Safeway and a Walmart there too, so really everything you need is close by. You will generally need to rent a car to get here from the airport, plus get to the stores and to other island tourist spots if you want. It's about ~$35 a day to park.
We love the lagoons, pools, and activities for our little kids. Never have an issue getting a chair at either the beach or pools, but we generally depart before the Christmas rush. There is a very large 'reflection' (AKA Adult) pool and hot tub that kids aren't allowed in, but it's near everything else so you'll still hear kids playing at the next pool over. The walking path is well lit, beautiful and safe to walk/jog at all hours back and forth to the other hotels. The bedroom units are spacious, clean, and nicely decorated. Very well insulated, we can't hear much of what's going on in rooms next to us and never hear anyone above us.
Like other reviewers have said:
1) no, there isn't special treatment just because you are a big Marriott Hotel Points guy. In general all guests are treated in the same nice way -- they leave you alone but are happy to help when you ask for it. This is a vacation club, not a standard Marriott hotel. Points are treated differently and it's actually kind of nice they treat everyone the same!
2) Yes, the toiletries are just ok, but if you are staying for 5-10 nights hopefully you plan to bring/buy your own shampoo instead of mooching tiny bottles off the hotel.
3) Yes, you are responsible for keeping your room as clean as you want it. Maid service will bring towels/toiletries daily, with a 1 time vacuum/bed change mid-week for, or you can pay extra for maid service more often. Again, this is a vacation club resort, they are trying to save owners money by not offering over the top unnecessary hotel treatment.
3) Food is typical of resorts, more pricey and not super great (tho we enjoy the Disney character breakfast at the Aulani and have had some nice meals at the JW). The food at the Vacation Club is ok for a quick burger/fries, but it's nothing special, and it's about $50 for lunch for two. If you stay in a villa/suite, you have a full kitchen, so you can cook a lot of your own meals. And there are plenty of grills on the property to BBQ.
Other: free internet, lots of stray sand toys for everyone's use, good sundries shop with Starbucks coffees and a nice selection of ice cream. The latest check out we've been able to get is 11am, but they do have a very nice policy of providing key cards for the shower/locker room at the pools and the bell service will happily store any luggage and allow you access multiple times a day. Also the bell service has cold storage, so if you get there prior to check in and want to grocery shop, they'll hold all your food in the cold lockers.
If you have kids, love Hawaii or want to try it for the first time, and don't necessarily want the hustle/crowds of Waikiki, this place is worth staying at!