I think real. Although I didn't read all of the article I think the main thrust was that since 2pi appears in so many places in math that a constant based on the ratio of circumference to radius rather than diameter would be more appropriate. Realistically I think there are better ways to spend your time but ....
Not exactly, since there is only one constant to convert (not many units) and the conversion factor is very straightforward (2 pi = 1 tau instead of 39.37 inches = 1 meter). But yes in that many people would have to change their ways.
