Just did the day trip on the Mamoni River. Aventuras Panama did a great job. Only two of us were going, but they still ran the trip. The trip is very scenic, and we saw a sloth, many birds, butterflies, and iguanas. The first half is more mellow with numerous moderate rapids to keep it exciting. The second half is more challenging. However, you do a short walk around the two dangerous areas, and the trip never felt unsafe to me. Plan to get wet though! Edgar and company did a very professional job. I've been lucky enough to raft many places, and this was equal to or better to any of them.
Visited October 2013