Vacuum advance information and myths

Clearly, there are two ways to run vacuum advance. The manufacturers ran MVA on some vehicles. The Big Block Chevelles were one example. All that's necessary is to adjust initial timing accordingly to whichever vacuum you are using. Whose to say one way will work better across the board for everything? How dumb does that sound. I know from my personal experience ported has worked best for me. Even with my high compression, big cam slant six, ported works better and yes I did try manifold vacuum. Ported is a much smoother transition and that's where I'm keeping it.