We've always used Crank Bros Candy pedals on the tandem. I tried Speedplay X, Crank Bros Egg Beater, and Crank Bros Quattro before settling on the Candy (S, Ti, 2, or 3) for all bikes. The OP should note that Crank Bros cleats have two float options, depending on which cleat is installed on which shoe. We always use the cleat with the "dot" on the right shoe (15 degree release vs 20 degree release with the "dot" on left shoe).