I've used some bloody awful editors over the years. Editing multi-thousand line COBOL files with Edlin was particularly unpleasant, but then so was the screen editor (hah!) on NCR centurion terminals. Editors in ITX and IMOS were also, erm, idiosyncratic. I learned vi in about 1986, and it's still with me, which is a very strong plus point - I can still just get stuff done with it. I recall how happy I was when I found a vi for DOS.
But then, editing source with Wordstar 4 was also interesting.