This is our 2nd time staying at a Marriott timeshare and I will say that the location could not have been better for our family! I will say that if I could give a 4 1/2 star I would, but since I can't, I don't think it's fair to give it a 4 stars, so I'm giving it a 5 star. And I will explain why 4 1/2 stars below...
First of all, to keep something in mind. The resort is located on the south side of the island, the very south actually. So if you're planning on spending most of your time on the north shore, the east side of the island... then this location might not be for you since you'll be spending a lot of time driving.
The hotel is located in Poipu and the beach is Poipu Beach. If you're a beach person, and I assume you are since you're going to Hawaii, this is a wonderful location to stay in!!! The view just walking along the beach is GORGEOUS, make sure you go there for a peaceful, relaxing walk when the sunsets, the view is something we're still talking about. The beach is so pretty that my mom was actually very happy just staying in the room and then take a walk on the beach without leaving the property. And Poipu Beach is actually the best spot for snorkeling on Kauai, so you get to have the best snorkeling location without leaving the resort!!! There are TONS of different fishes in the ocean, just a few steps away from shore, so even if you don't swim, you don't need to worry because you can see plenty of creates in the shallow end.
We also saw monk seals and a huge sea turtle on two separate days, just sun bathing in the sand.
This is actually why I would give this property a 4 1/2 stars instead of the 5 stars.
The room we stayed in had 2 bedrooms. The rooms are very nice, and comfortable. The kitchen is fully equipped with all the necessary tools/utensils for those who would like to eat at "home." The reason I would give 4 1/2 stars is because in one of our bathrooms, the shower stall actually smelled a little bit mildew-y. It's not bad by any means, but because I'm so used to the Marriott standard, I found it a bit surprising that this happened since Waiohai is such a prestige resort. Another thing is that our dish washer actually malfunctioned during our first time using it. The water inside spilled out in the middle of a cycle and we actually had to stop the machine and couldn't use it for the remaining of our trip.
The resort ground is beautiful. Very well manicured "falls", ponds and pools. And I love that the wild chickens are just everywhere on the ground. You would think that with so many chicken on the island, it'd be impossible to get a decent sleep since the chickens all crow at random times throughout the day. But we definitely did not have that problem. The resort lobby isn't very flashy though. It's quite modest which was surprising to me, but then I figured it makes sense since we're on the island Kauai.
There's a convenient store located next to the lobby where you can buy things that you might have forgotten to pack such as pain killers, eye drops... etc (you know, the usual stuff). This is a very small store and the things that are available to purchase (everyday item things) are actually surprisingly limited.
All in all, the resort is wonderful and I really don't think anyone would be disappointed staying here.