Good point between the two! I'd prefer being in neither if there was engine failure over mountainous terrain haha.

Imo, the biggest difference between the two is that fixed wing aircraft have a lot more time available to them to correct for a case of complete engine failure. While it would still be an issue over mountainous areas, the plane would certainly have more time to glide and find a place to land imo. (Assuming it's at a higher altitude than a helo would normally travel). Not that this would make it easier or anything. Just that the total amount of time you have to correct for an engine failure is far greater in a fixed wing craft then a helo, generally speaking.

That being said, the training you're mentioning is excellent, and I have nothing but respect for Helo pilots. If anything, they have to be more dialed in than fixed wing pilots as there's a lot more that can go wrong quickly. So likewise, the training needed to be a good Helo pilot far exceeds the training needed to be a good fixed wing pilot. (At least imo). To that end, I would 100% rather be in a Helo with engine failure as it's far more likely the pilot actually knows what to do, and is trained for it too 😉