I always suffered from the attitude of "Well....let's give this a try and see what happens...school of thought." I studied up on the topic and carefully considered what I was doing....but nothing beats experience....VRS, Settling with Power, RBS, low speed UA's....tail rotor failures....hydraulic failures....stuck collective....all sorts of fun things. Mind you I did all those under controlled circumstances and always with well thought out parameters....and never really scared myself or those with me beyond what my normal flying skills did anyway.
While instructing when a Student let the aircraft get away from him...I refused to take the controls unless it was really necessary and instead forced the Student to regain control....all the while reminding them I would not always be along for the ride in the future and they had to be able to make the Helicopter or airplane do what they wanted it to do.
Simulators are just that "simulators" and do not actually replicate the handling qualities of the actual aircraft.
One short coming is the delay with the aircraft computer and the visual computer....some are better than others but there is always a slight delay between the pilot's input and the movement of the visual....as even electrons travel a bit slower than the human eye can perceive movement on the visual and bounce it off the brains signals to the hands and feet.
The more you can experiment with the actual aircraft the better off you are....but do it very carefully.