straight drop holsters are faster if you tend to draw straight up and then "punch" the gun out toward your target. faster if you are longer waisted or shorter limbed
the FBI cant (11 degrees) is faster if you draw forward, bending forward at the waist and pulling the gun "forward" out of the holster toward the target
the further back you wear your holster the more the cant will help during the draw. if you think your holster is slowing your draw, you might try moving it further behind your hip.