The online booking states "minimum 2 people" and only let's you book for that. I contacted Manifa directly and they agreed to book me for this trip with the understanding they would move me to different group tour if their was no other participant. In the end I paid for 2 slots and had a private tour. Manifa also was able to rearrange the return trip at the end of the day as we finished 2 hours early. Great service from Manifa Travel.
My guide Kwon (probably the same others referred to as Kwang) was knowledgeable and fun. The village we visited was a real village, not a showcase. During the hike Kwon gave me a lot of information about all local cultures, Lao history, plants, and animals. Fantastic stories were presented as such rather than as reality. Having lived in Myanmar for 10 years, we discussed a lot about similarities, both in culture and landscape.
The trek is not strenuous, but there are some places that require surefootedness. It begins at the village and winds up and down through a couple cultivated valleys before climbing into the jungle and then dropping through the jungle down to a large spring that supposedly feeds the falls. From there you make your way down to a dirt road, which you follow for 5-10 minutes before reaching another jungle trail leading to the head of the falls, where you have lunch before descending to the foot of the falls. After several hours alone in the fields and forests, the humanity at the bottom is a little overwhelming. So, of course, are the falls.
We ended with a walk through the bear sanctuary, but did not visit the butterfly center. I think the overall distance was about 9km.