Yunnan Adventure Travel did an excellent job with our tour. I was travelling in Yunnan with my two parents for a bit more than a week. Our guide took good care of us, she's really nice and professional. She was very patient with us, even if we changed our plans several times. She was quick to answer and bent over backwards to fulfil our expectations. We had a very good experience with Yunnan Adventure Travel, we felt that they were offering us what was best for us and that they were honest about all the options we had. They are nothing like some tour agencies in China that will do anything to make you pay things you don't need or make you buy options that are more expensive.
The only thing they could improve would be to give travelers a leaflet with the precise summary of their tour and the schedule for each day. Since we didn't have guide, only a driver who didn't speak english, it was sometime difficult to communicate. We knew we what we were supposed to visit, but we didn't know the exact schedule that the driver had (in chinese), so it created some confusions during our trip. It would have been nice to have something like that.