The hut, hut, hut sit and switch is more effective and efficient than twin double blade paddles for competent users of the bent shaft. Couple of reasons the main being the proximity to the gunwale of the bent- the greater the distance your paddle enters and leaves the water from the centerline of the canoe the greater the energy expended in lateral force (yaw)  (or waddle if you prefer)as opposed forward. Bent is very good if used with strokes ending before your lower hand reaches your hip (optimizing the length of stroke in which the blade is near vertical) and along a path that parallels the center line of the hull not the gunwale. Bent also gains efficiency from the relative low mass of the paddle (A ZRE power surge light weighs in at a mere 7.5 oz).

Double blade is good if paddler is poor or slow at switching or lacks the discipline to maintain the shorter stroke, quick cadence and fidelity of force direction required for efficient use of bent.