I think this is one of those "religious" wars things - although us proportional fonts people are much the minority.<p>I've used proportional fonts since the early nineties and written thousands and thousands of lines of code since then in a proportional font. I have occasionally tried to go back to a fixed width font but I can't be bothered trying to get past the "it makes my head" hurt stage. (and likewise I can't imagine a lot of fixed width people getting past that stage going in the other direction).<p>We can rationalise our choices all we like but I doubt that there is any serious advantage or disadvantage in either.