Overall I had a wonderful stay at the Zephyr Palace, part of Villa Caletas. The Palace has about 8 suites and a small infinity pool overlooking the jungle and ocean. Our suite has it's own outdoor jacuzzi (I think most do in that building) and a separate spare bedroom fit for traveling with your personal assistant. We were one of 2-3 couples there during our stay so we had a semi-private experience.
The property also boasts a private beach outfitted for lounging and relaxation, accessible by a long walk or a convenient shuttle service. The beach, however, is not suitable for swimming (rocks). And if you need a change of food or scenery, it's about a US$30 cab ride into the town of Jaco.
Service at the Palace seemed a little slow though. Being on the far side of the property you need a pick/drop off just to go to the main restaurant. On one occasion the cart did not show up and on another took over 30 minutes. When we ate or drank at the pool at the Palace, our order took ages. It seemed our waiter was the only person working in that building and was perhaps running back and forth to attend to other duties. It's not any fault of his but just seemed understaffed, perhaps due to the small number of guests in the Palace at that time.
The Zephyr Palace also appears to be a wedding venue and on a few occasions there was a flow of visitors and sightseers coming through as we sunbathed and ate our breakfast pool side.
All of this is still only a small blemish on an overall wonderful experience. I would definitely recommend the Zephyr Palace to others and may even return sometime myself.