I hate double spacing. And you can dismiss that as a personal preference, but there's a problem with it, objectively speaking. Normally, whitespace is collapsed in HTML and it's a moot point. But not in WordPress.
Now, let me pick on patio11. He uses double spacing in his articles. Not a big deal, right? But the extra spaces causes unintended indentations in paragraphs. I know it shouldn't bother me, but it drives me bonkers. For example, I see it in the second paragraph here: http://www.kalzumeus.com/2011/10/28/dont-call-yourself-a-pro...
Now, let me pick on patio11. He uses double spacing in his articles. Not a big deal, right? But the extra spaces causes unintended indentations in paragraphs. I know it shouldn't bother me, but it drives me bonkers. For example, I see it in the second paragraph here: http://www.kalzumeus.com/2011/10/28/dont-call-yourself-a-pro...