Every aerial photographer has his or her preferences. So do I, which is why I use a pendulum almost exclusively.
It is easy to build, it has no movement around the Z-axis, it has now proven itself in almost all conditions of use, it carries all RIGs with different weights satisfactorily and it can be used at almost any line angle.
The pendulum rod has a length of approx. 75 centimetres, a rubber band dampens the movement as described by Michael Haugrund at the time.