Airsmount,
I too have flown both FW and RW commercially, and I'm not sure where you've trained/worked in rotary, but I have done hundreds and hundreds of Full-on Auto-rotations covering every type I fly.
I do agree with your assessment that it takes more finesse and skill to handle an Auto than the loss of one turbine, unless that's a V1 cut... then same same, but different. As long as full on Autos are practiced regularly, the working pilot is every bit as likely to pull it off safely as the working FW counterpart.
Comparing apples to apples, I'd rather have an engine failure in a single engine helicopter than a single engined airplane, weather the terrain below is good, or if it's poor. In the multi, it depends, an engine out in a piston twin at the wrong time can/will be disastrous if not handled exactly right, but in an aircraft like the Challenger, or almost any airliner these days it's a yellow light event. The 212 fully loaded while hovering/slow/low loosing one is trouble, the AB139.... not so much.
At the end of the day, I'll take the helicopter.
RH