I feel like this would drive me nuts when dealing with code, CSVs, or other kinds of data I'd commonly be viewing with a mono font. Two adjacent rows nearly identical rows might look more different than they really are, say because an "im" changed to an "wm" and the "m" is moving around.

That's not to say it's bad at all, just that I think it wouldn't be right for how I'd mostly likely be using such a font.