on what it depends that some copters ( as the phantoms ) show fast heavy vortex ring states and others not . E.g. my old hisystems x8 kopter could fall from sky without any gas nearly in freefall and it behaved completely controllable. alao the mavic2 can descend with 10m/s ( modded ) and looks pretty safe . the phantom starts to wobble already with 5 m/s . on what it depends that the drones behave ao different in this important aspect.