We spent 9 days on the Atata island, went there off season, and we had the whole island just for ourselves. They upgraded our fale for free to a beachfront one, we loved it so much!
The food was delicious for a good price ($8-9 for a lunch, we could have dinner from the lunch menu as well).
Our daily schedule was the following: breakfast, snorkeling in the morning, lunch, kayaking in the afternoon, dinner, sleep... for 9 days, and the island is so beautiful, the reef is so close we didn't get bored!
People were very friendly, we visited the village twice, and learned a lot about Tongan culture.
We will definitely go back.