We stayed at Lomani Island as part of our honeymoon last year. It was great, very friendly and adults only. We wanted to do lots of nothing, but they had activites if you wanted. I spent my time on a hammock by the pool, or on the daybed by the pool or lounging by the beach...so hard! It's part of Plantation Island (same owners), but kept separate (Plantation Island is the family resort). Food was average, but good enough - no need to buy the package, it was cheaper to just buy meals as we went.

If we'd had the money, I wanted to go to Tokoriki Island and stay in a bure with a private pool.

Also, we didn't bother with the main island - just flew into Nadi then bus/ferry to the resort island.