I had my first ayahuasca ceremony at Nihue Rao, and it was a profoundly moving experience. The grounds are quiet, clean, and well maintained. With more amenitiesn then one would expect that far into the jungle. Plenty of support staff are around and are interested in answering any questions or concerns you might have.
The center is a serious place for the application of plant medicine, and the staff there do their jobs with a professionalism that surprised me.
I may not agree with all the points of view of Nihue Rao (I lean towards a synthesis of western thought with spirituality), and the shamans themselves seem distant. However, there is no doubt they are great teachers of their craft and care deeply about the personal growth of their charges.