The response of those engines really was dire!
The difference was, in my experience with both metal and plastic, that the plastic blades would accelerate more than the metal ones under conditions of light or nil loading. An example is autorotation whereas metal blades with not go fast enough for a needle split unless above 6,000kgs. Plastic blades with achieve a needle split at any weight with the result that the engines back off to the idle stop which is why they take longer to react.
Another reason why the alternator trip had a delay added.
Always remember that on a zero speed EOL to apply full left pedal as the alternators trip off with the lever around your ears or the yaw/collective interlock will point you over your right shoulder.