Interesting point, QDM, particularly on the subject of field choice. As you say, lower being (arguably) (almost) better wouldn't work for all types. It struck me the other week whilst chugging around in a Cub, at low altitude in some claggy vis, that it was a jolly nice type of aeroplane to have a mishap in, particularly as everything happens so slowly and it can land so short.
When as a pre-solo student the engine stopped at 1000 feet agl in a not very glidy type, the instructor, who had been busy yelling at me until the thing went phut, faffed no faffs and went straight for the appropriate field, no messing. He had time to get in a Mayday call, which assured a prompt lift to the pub afterwards, but not time for much else (he even stopped yelling at me, which was nice).