I rowed Hells Canyon a couple weeks ago, for the first time (have rowed the Main Salmon 4 times and the Rogue 12 times). Flows were around 13,500 to 27,000 cfs during our trip. You are correct that the Snake is bigger water than what most people do the Salmon or Rogue at. Bigger, more powerful, pushier, bigger holes, bigger waves, etc. The other huge difference is the daily fluctuations due to dam releases - as you can see, daily max is roughly twice the daily minimum. This can affect your runs of the two biggest rapids (Wild Sheep and Granite). You're right, the rapids are generally not technical. Square up, rig to flip, keep your momentum up. Even the class II and III wave trains can be big and pushy, and could flip an inattentive boater. Scout Wild Sheep on the left, Granite on the right. Try to time your run of Granite at 20,000 or above and the "Green Room" will be in. It is an obvious run down a gigantic smooth green tongue, then up and over an equally gigantic green wave - incredible! Lots and lots of jet boats. It is a beautiful canyon with enjoyable water and worth doing. Enjoy!