Never stayed at Xanadu, but, when I visited A.C. last August a buddy and I hired a boat to take us up and down the coast, and stopped in to Salamander Hideaway for a drink. It was very pretty--and very secluded. When we were there (in low season), no one was even staying at the place. The staff was having breakfast in the dining hut (we stopped in for a drink) and some of them were going fishing later that day to kill the time. The only thing in close vicinity was the Habaneros plantation, next door.
The facilities looked nice, but very basic. The huts were a little smaller than I would have expected (one of them was open, and it seemed like the bed took up most of the space). It looked like it might be a fun place to stay to get away from it all for a couple days, but you'd have to understand exactly what it was you were purchasing when staying there, or you might be disappointed.