I have ran the class 3 side
its not two bad if you know what you are doing !
but i have also been trained in swiftwater rescue and have 3 years of white water raft guiding .
i would rather run the class 3 side in a drift boat ,you got more room to move around .
you also have to remember that they have built the drops for the kayakers to surf
let me tell you one thing dont hit it sideways or you will have a really bad day !