I’ve had the Thanksgiving Buffet at the Hyatt, and it was fairly typical Large Buffet fare. The key is to make sure you get your reservations in very early, as it seems it is the Thanksgiving buffet of choice for everyone on the Poipu side of the island. Not only does everyone from the Hyatt eat there, but all the neighboring resorts come there for dinner. When I tried to make reservations a few weeks in advance the only thing I could get was something like 3:00.
Gaylords would be nice, but I have no idea if they do anything for Thanksgiving. The food is pretty good and it has a very nice setting. If you are into the luau’s theirs is better than the Hyatts. Personally I’ve done enough luau's to last me.