I'm firmly in the double-space camp, but for a reason not mentioned in the article: A sense of finality. Two spaces ends a sentence. The double-tap means it's time to move on, not meander in the trailing thoughts or follow-ons that commas often give rise to. A double-tap's finality is partial, and far from being as jolting as hitting Return; flow will continue, double-space's finality is linking, a small leaping limp, a tactile and audible pirouette, to what comes next, and simply can't by substituted by a mundane, routine, middling single tap.

I draw a line at four spaces after commas.