I have been using the Manfrotto 393 Gimbal for about 15-years...
https://www.youtube.com/watch?v=Rzy6Jddl90E&t=26s
IMO it is one of the best mounts for action photography
I learned about this rig from Romy Ocon, an excellent BIF photographer from the Philippines.
https://www.youtube.com/watch?v=qEfeV8AjG_g&t=124s
But, why isn't this rig more popular. IMO, much of the lack of popularity is because of the inept marketing of Manfrotto...
1. Manfrotto has marketed this unit und several designations over the years.
2. It seems unreal but. Manfrotto persists in advertising this rig with the camera mounted upside down, while it seems that everyone else uses this rig with the camera mounter on top of the swinging mounting bar.
3. Manfrotto also persists in stating that you cannot use a flash on conjunction with this mount! I contacted Manfrotto in 2007 and asked how to mount a flash using their mount. Manfrotto replied that it was not possible to use a flash with the rig! However, a simple aftermarket adaptation using a "C" shaped bar of flat aluminum makes adding a flash easy with this fig. Manfrotto could easily add this as an accessory.