Emacs puts two spaces after a period when reflowing paragraphs. So I've been going with that default for years as the path of least resistance. Since it makes

Emacs puts two spaces after a period when reflowing paragraphs. So I've been going with that default for years as the path of least resistance. Since it makes monospaced text slightly more readable and most rendered text output (TeX, Sphinx, Markdown etc.) ignore the additional space and omit it from their output, it doesn't have any significant detraction to me as an author, so I'll continue to live in the two space camp.