Had arranged the slow boat trip through email with a guy from Chiang Khong, he showed up with a van, drove us to the ferry and got us organized for Lao immigration. Lots of confusion getting from Thailand to the boat in Lao but it went smoothly and a couple hours later we were on our slow boat.
Amazing scenery along the river, our boat wasn't crowded, we got food, drinks and stopped at two remote hill tribe villages along the way (One Hmong and one Mien). We had a guide on the boat who was raised in a hill tribe village and was an opium farmer until the government encouraged him to. Learn English and move to the town. The village visit were more interesting with him because he could speak the local village dialects.
Stayed overnight in Pacbang in a nice hut with a deck overlooking the river. Last stop before Luang Prabang was the Pak Ou buddhist caves.
Enjoyed the river trip, saw lots of water buffalo, native villages and even one elephant working along the river.
The hill villages have very poor living conditions, worse than we saw in South America, they had serious health issues in the mountains so the government relocated them to the rivers, hopefully it's an improvement. But it doesn't look good.