It is mainly used in drag racing. It reduces weight by not having the dog bone, and helps get power to the ground my eliminating unnecessary linkage (aka dogbone).
Not recommended for duning, or any other riding really. It worsens suspension geometry and proper travel of the rear shock.
I would recommend it for drag racing purposes only :thumbsup:
Edit: yes, the mounting location on the swingarm is flipped to the underside, and nothing has to be changed on the frame.