Isn't that the point of the grip safety? IIRC even John Browning never saw the need for a grip safety when he designed the 1911, it was the US Army that wanted it, precisely because they thought that without it, if the pistol fell from a cavalryman's hand to the ground (when on horseback) it would fire.
I can't remember where I read that, although it may have been in an issue of the Book of the 1911......
To answer the original question, I'd go with the Series 70 because I'm a keep-it-simple-stupid kind of guy. AFAIK, the Series 80 firing-pin block was not put there on demand from engineers/designers, but from lawyers.......the fewer parts in a device, the less chance one of those parts will break or not function right when you REALLY need the damned thing!!!