:-) Actually, we are using the "original" behavior used by QTVR which was the first implementation of interactive panoramic images on computers back in the 1990's. It is the paradigm that you are the camera, and you are moving your eyes.

The click/drag paradigm is good for maps, because it uses the analogy that you are grabbing and moving a map.

Anyway, this is a huge debate these days in the pano photography community. It seems that google streetview / google earth are somewhat winning at this point in terms of this type of navigation....