The Gimbal is used to precisely move objects around the world while keeping them locked to the axis. You can use this for smooth rotations and even duplication.
Right Controller analog stick press - Hide and show the gimbal
Right Controller Trigger - By using the trigger you can grab the gimbal and offset it from the center of your mesh.
Left Controller Trigger - By grabbing the ring with the trigger you can snap rotate the model. With the grab button it smoothly rotates.