Off and on for 15 years with different partners I have rode tandem as the stoker. Personally I do feel it's more stressful than individual riding. Some partners were easier to ride with than others - good partners communicate alot, every move, turn, etc. but here's the thing for me with a tandem - speed and that lack of control. Yes I am a control freak and as a stoker - you must give your trust over to the captain. And speed - nothing moves faster than a well-working tandem - going fast, not being to see, no control... to me that's stressful!!!!