BOAC;
The AB sidestick fits the hand and the arm is supported by a very adjustable arm-wrest, (up-down, high/low angle) and the sidestick can be easily controlled from the wrist or even just the fingers if placed at the top of the stick. It is heavily damped. My point was, this is a very good control system which is natural and easy to get accustomed to and use even in heavy turbulence. If we are discussing severe/extreme turbulence or jet-upset conditons however, no aircraft is immune to high 'g' loads in terms of reaching/moving the controls, column/wheel or sidestick, especially with the likelihood of flight bags and everything else that's not tied down flying around the cockpit, (possibly in the dark)...
For background info, the sidestick does not move ailerons or elevators. The sidestick requests a roll-rate and a 'g' load. The FCPCs interpret the requests and provide the necessary commands to the servos, through the C* (fbw) laws which have been discussed. This is essentially the same as CWS - Control Wheel Steering - not sure the Boeing has it but the L1011 did.
The process is, for practical purposes, instantaneous - no lag between request and response. Also, the autoflight system, being fbw, keeps the aircraft in the last "known" attitude until another input is made, which, if one thinks about it, makes complete sense. One can "set" the attitude, leave the airplane with hand off the stick and the fbw autoflight system will "keep" the attitude until another input is made changing the attitude.
Even in heavy turbulence, the system (fbw, without the a/p engaged) will attempt to keep the aircraft at the last position established. You mention sensitivity levels - that's not so much an issue with the AB sidestick as understanding what's going on out on the wing - while the full-time fbw system is trying to maintain the last aircraft attitude, the FCPCs will also be interpreting the second-by-second sidestick manual "requests" by the flying pilot so will be busy satisfying both inputs.
For these reasons, the notion of "coarseness" is not so much applicable in understanding the system as is an understanding of what the ailerons are doing out there on the wing in response to all inputs, fbw & manual, and why. There are many cases in which over-controlling is an issue in the AB for exactly these reasons., (I note the thread on the Hamburg accident).
I have posted my biases lots of times - I am not a convinced Airbus pilot trying to "sell" the design or tout its benefits over other types. I'm describing the machine from one pilot's point of view. There are in my view some things that this design must answer for but with solid training, adherence to standards and continuous testing and recurrent training, handling the Airbus is a non-event. It was this level of appreciation for the design that I was making a point about. That said, your own experience re the stick in the Whirlwind, albeit a long way from the AB design, does cause one to sit back a moment.