Fundamental sounds meaningless to me. Talking about statements and words with meaning I am sure, that Tau is the more useful circle constant out of these two:

Fundamental sounds meaningless to me. Talking about statements and words with meaning I am sure, that Tau is the more useful circle constant out of these two: less symbols, conceptually clearer equations. Also turn is generally a more useful measurement unit for angle than radian or degree, but radian has its own merits, and not disposable, unlike pi.