Power
Nick
I do not agree with both of your conclusions. You perfectly know that power can be decisive in many occasions in getting out of troubles without considering the engine failure case.
How much power is too much?
Power is also associated to A/C controllability in hover conditions that is also a safety issue.
I agree with you as far as the penalties you have to accept when you "over design", but to me, this is going towards safety, even though this costs money (as always).
The future models of the 139 will address this issues and increase payload but without penalizing the big plus of this machine.