The Python's cylinder rotates clockwise. The 686 goes counter-clockwise. In the northern hemisphere, the force of the rotation of the earth assists the Python 's action, making it smoother.

Also, the Python has left hand rifling twist. This also takes advantage of the earth's rotation, and also explains why so many great curveball pitchers were left handed.

Of course, our military struggled with their issued Colts when empire building in the southern hemisphere, and for the same reason, little if any baseball is played south of the equator.

So that's why the Python is the more desirable handgun.