And in stable flight, be it a hover or forward/sideward flight, THERE IS NO DISSYMMETRY OF LIFT.
I think that is probably correct in theory AC but not in practice since a helicopter never seems to be in stable flight.
In an unstabilised heilcopter, no matter how accurately you set it up in the hover or at a specific height and speed, you are always making small control inputs to prevent the aircraft going off and doing its own thing.
In a stabilised aircraft the actuators in the SAS/ASE are constantly working to do the same thing. Or in the AP in a more complex aircraft.
There are too many variables - wind gusts, turbulence, the wake from the preceding blade, the disturbance of a blade passing over the fuselage, MR/TR interaction etc etc and as many have said here, the reason a helicopter is more difficult to fly than a FW is because it is inherently unstable.
Try taking your hands and feet off the controls in an unstabilised helicopter in the hover and see how long you last
