For me, the second space after the period is a wasted byte. The same applies for the just one space after the period if you are actually moving to the next para

For me, the second space after the period is a wasted byte. The same applies for the just one space after the period if you are actually moving to the next paragraph (just a CR+LF) is enough (more than enough in Unix). But what I really dislike is the preceeding space before the question mark. That really messes up my brain sentence parser (and many word processos too).