The guides who work with Bundu Adventures are among the best. As someone who has never been whitewater rafting before, it put my mind to ease to have this level of expertise accompany me and my friends on the rafting experience. They had good stories, pointed out interesting landmarks, and knew what to say whenever the waters got choppy.
The only thing I didn't really like is that they label the 'half-day' experience as being 6 hours long, which I feel is misleading. They picked us up around 8 AM, drove us to the start of the rafting area, and gave us a tutorial. That took up until 9:00 AMish, after which we had about a 20 minute hike down to the bottom of the gorge, where the river was. The rafting experience itself was only about 1.5 hours at most, but there was a lot of hike before and after (if you go on the full-day rafting experience, you can avoid the steep hike up to the top of the gorge that half-day rafters have to do). Over all, the experience lasted about 4 hours, including lunch time.
In the end, I would definitely recommend people to book these guys for a great experience - but know exactly how much time you're dedicating to this!