Brian has the Airbus FBW logic explained very well, however it is prone to serious misunderstanding by Airbus Line Pilots. The PNF can 'Dual Input' against a PF control anytime, but you get scolded very severely by the gentleman who shouts 'Dual Input'.
As someone who trains Ab-Initio pilots with either no previous FBW experience or very low total hours (our National Cadets for example) the issue of no feedback can be a little challenging. It was always reassuring as a trainer on a Bell 212 for example to feel or see the control inputs from the trainee, however the secret to the Airbus is to watch the attitude of the aircraft (and sometimes the trainee) and be poised on the sidestick (cyclic) with the thumb on the take-over push button (where the winch cable cut/ext load disconnect would be on a helicopter cyclic).
A classic issue with us is the flare for landing, either done too early or late - both equally "bad", the passengers usually notice the latter (as they limp off the aircraft with a slipped disk) and the "spy in the cab - FOQA" usually notices the former (long landing or tail strike as the float is progressively held off and the pitch attitude is increased until there is a strange scraping sound overlaid with the screams from the cabin crew in the back....)
In a sense FW are easier to take over since you are mainly guarding against over or under pitch with roll being secondary but still very relevant beyond 7 degrees. (see the korean-landing-in-hong-kong-horror-video).
With rotary issues there are more axes to take over in and would require considerable vigilance IMHO.
The beauty of FBW I have to say is the total lack of requirement to trim. If anyone has flown a well set up SFENA equipped Bell 212 (I know SAS, that probably happened three blue moons ago), it's very similar and was called 'Transparent'. With the Airbus FBW commanding a "G" load in pitch and a roll rate in roll the aircraft trajectory remains where you stop inputting onto the controls, it is literally point-and-shoot (within reason of course - top of a wing over excepted). The other great benefit are the provisions of protections which you cannot do with an analogue classic helicopter control system. Until you actually witness the effect of hurtling towards a Swiss cliff at 250KIAS, waiting for the EGPWS to give you the Whoop, Whoop and then applying full back sidestick (cyclic) and fully forward on the thrust levers to TOGA thrust and literally hang on the edge of the stall (with a safe margin) climbing at 6-7000 fpm out of danger it is hard sometimes to appreciate what 'protections' really mean.
In regard to the comments about 'feeling the vibration' back fed through the controls, I would venture to offer that in a modern helicopter like the 225 or 92 with 3000 ish PSI of hydraulic pressure doing the work for you, then the chance of 'feeling the vibration' would be near to zero.
TOD