The zoom in/out is nice, but its to easy to mess up your orientation so that you have to recenter the camera.
Both these are in 3rd person lock mode:
1) If you zoom out and hit a wall, or other obstruction it changes the position of the camera lock with respect to your body.
2) If you attempt to turn and zoom in/out at the same time the camera loses its lock, and rotates around your body a little bit more with every partial rotation of the scroll button..