Just returned earlier this week from a stay at the JW Marriott Ihilani and I think the other two locations will really pale in comparison (especially the Renaissance; I don't have first hand knowledge about the Waikiki Beach Marriott).

There is a lot to do at the JW to keep your family occupied and if you are going to rent a car you can certainly cover Waikiki that way (though traffic back to Ko Olina can be awful).

Additionally, you are close in proximity to Pearl Harbor. From there, we shot up to the Dole Plantation and then hit a few North Shore Beaches....absolutely loved Turtle Cove in Haleiwa....swimming with giant green sea turtles was fantastic!

As a parent of 3 older kids who just did a 2 island hop, I would strongly dissuade you from packing up a baby and a 6 year old for a third time. And I wouldn't say that a 3rd day on the Big Island is a bad idea

PS-Since Search is down, a word of advice.....careful on the upgrades. When I reserved what I *thought* was going to be ocean FRONT, it was 3 certs per night. It has now increased to 4 certs per night. AND the room I was given was on the side facing the industrial area and was certainly NOT fronting the ocean, though I did have ocean view.

Front Desk manager agreed and was very generous in compensating us.....but the room view was just not what I had envisioned. Nonetheless, a wonderful hotel and a fantastic stay..... you will love it.