Just returned from a 7 night stay here. Overall, we had a great experience. The hotel itself is gorgeous. Here are a few more of my thoughts:

1) The food is mostly good, although we found it to be pretty inconsistent. We liked Rio Bhongo the best. Chao Pescao was basically empty at night, probably because it's rainy season. We thought Ostra was overpriced.
2) The staff was very nice. On our last night at Chao Pescao, one of the bar tenders spent time with my wife and me teaching us to salsa. All the employees at reception were amazing.
3) Food and drink service were slow for the most part, except at breakfast.
4) Andaz beaches are pretty disappointing but the pools are very nice. If you're looking for a nice beach, we thought Flamingo Beach (about a 30 min drive) was the best in the area.
5) We had an unfortunate incident a few days into our stay. Our rental car was damaged. To be clear, we have no idea where it occurred. Although we noticed it one morning at the Andaz, I think it's unlikely that it happened there. Prior to that we had valeted at the Beach Club, Four Seasons, and Andaz. We know it did not happen while we were driving. It was either a hit and run or one of the valets we had used somewhere caused the damage. Andaz was very helpful in looking into the incident. They reviewed their security cameras and didn't find anything. So we're now dealing with Avis to process the claim. I only had the mandatory minimum rental car insurance through Avis, which doesn't cover anything in this case. I'm going to rely on my Chase credit card. I think it could be an expensive fix given that it's a foreign car and all foreign cars seem to be very expensive in Costa Rica.