Obviously Eric you haven’t tested the latest Campy.
To answer the original poster, one is hand made in Italy by a company that makes parts for Ferrari and NASA. The other is machine stamped in Taiwan by a company that makes fishing gear.
Shimano has a bigger share of the world market and that’s why I own three bikes with Shimano. But then the same thing can be said for General Motors and why I have a Pontiac. However, GM does not make my dream car and when I can eventually afford my dream road bike it most certainly will be fitted with Campagnolo Record.
In practical performance terms either will get the job done equally well. Campy seems a little smoother IMO. One advantage of Campy is that the shifters can be rebuilt while the Shimano shifters are thrown in the garbage and replaced.
There is a definite snob appeal about Campy, not so much with tri-geeks, but certainly among the roadies.