I just came back from a 3 day retreat at Bhavana Society. It was instruction for beginners in mindfullness meditation. In short, it was a good experience. It was at times so hard that I thought I'd have to quit early and go home and at other times I felt I was making real progress. Some people DID leave after the first day, but I don't know what their reasons were. It started Thrusday at 5pm and ended 11am Sunday, although I hung around for lunch and to talk to the monks a little bit afterwards. It was a silent retreat, except for two brief quention periods. We followed the eight precepts. My wife also attended, bringing a whole class of additional challenges. More details later.