We went to Eranda Spa 3 out of the 5 days we were in Koh Sah Mui. Mid December 2012.
The massages were excellent and the whole experience was very rejuvenating. The environment was set on a hill with 8 little villas as your massage rooms. We had a chat with the owner and she was very pleasant and she told us that her masseurs have been with her since she opened the spa 10 years ago.
We will return to this spa when we visit this island again .