Nope, definitely vi. I have a vintage book about Unix written ca. 1980, and the author's concern was that "vi's code segment will fill up most of the main memor

Nope, definitely vi. I have a vintage book about Unix written ca. 1980, and the author's concern was that "vi's code segment will fill up most of the main memory of a large PDP-11, leaving you little space for the text you're editing". They considered their university's heavily modified fork of ed (the standard text editor, remember?) to be a better choice.