Not a user, but I've decided at some point to use it to write a `.tex` report. Insightful experience:

(i) fixing mistakes is costly: one needs to think more/be more cautious;

(ii) one needs to grow a "mental image" of the codebase;

(iii) which encourages to be more regular and austere/simpler, while training memory;

(iv) the lack of features encourages creativity, e.g. using "good" regexps to navigate the code; a common example is for C functions to be essentially uniquely identified with `^foo\(`, when the functions are defined with:

  int
  foo(…) {
  …

The dumber the tool, the more intelligent the user has to be, and reciprocally. Of course, there are practical limits; that's just the general idea.