I can throw my real life experience into this debate. I worked for 7-8 years as a professional whitewater guide out of Ohiopyle, PA. Guided on the Yough, Cheat, Big Sandy, and Russell Fork. The first few years it was awesome work and I loved doing it. After three seasons it became a drag to the point that I stopped kayaking for fun. If I wasn't getting paid then I didn't paddle. It has taken years to get the desire back to paddle again. Now when they call me to fill in on busy weekends I politely decline unless I'm the last resort. I do enjoy fishing from a raft and that is about the only time I get on the river for fun.