You can do rotational rows with both hands on the rope or in a unilateral fashion, the way Pittsburg Pirates outfielder, Austin Meadows, is demonstrating in this video
The benefits are similar to the bilateral version, but there's additional tension on the upper back and lats. That's because the less restricted single-arm position allows slight rotational movement of the upper torso. This further increases the range of motion in both the stretched and contracted positions creating one enormous contraction on each rep.
The core is also forced to stabilize the movement and resist excessive rotation thereby increasing spinal rigidity. This enhances the stimulus to the upper back and lats. The effects are further magnified when performed in a standing fashion as shown in the video.