This was my 3rd time rafting with my sons after having done so in Ayung River, Bali and Thailand. None of those had prepared me for the most awesome & thrilling ride I have ever done. Maybe due to the recent downpour, the water was extremely fast, but not very deep with many boulders/rocks which made it more thrilling. Alam guides were very professional and experienced that we felt very safe despite the precarious ride. I saw many beautiful scenery (waterfalls, jungles, birds etc even a topless girl bathing by the river). Going down/up the steps to/from the ravine/ river was not as bad as what I have read in some of the comments here, though it can be a bit slippery if it rains. My feeling is it is not very safe for children below 10 as the condition can be quite rough during the wet season. The 3hrs ride (with 2 stops to rest) and 16km distance was amazing that you would not notice the time. Do bring your own camera so that you can take pictures during the stops, but you must put it in a waterproof bag as it will be very2 wet in the raft. Alam have people taking some photos at some strategic location which they will sell by end of the trip.
Overall, it is worth every cent you are paying & you should try it if adventure is what you are looking for.