Spent the last week of Dec in Rarotonga. We really enjoyed it. Raro is the largest of the Cooks, however, it is still small. We found it to be quiet with very friendly and helpful locales. We always tried new restaurants and never had a bad meal. We stayed at Moana Sands and really loved it. The water was warm and calm because of the lagoon. Lots and lots of foliage. I kept saying I felt like I was on the island from Lost. We rented a small car but there is a reliable bus system that circles the island. Only thing to realize is that that the diving/snorkeling is not outstanding. We snorkled every day in front of our hotel. The reef was not in good shape, but we still saw fish. Seemed to be better the further out you went. I suspect some of the other Cook Islands may be better in this regard. Would go there again.