Really? I could have sworn I've heard people say in one of them Forgecraft vids that the big thing about the fluid registry is making any registered fluid placeable in the world.
But well, if the one who wrote it tells me I'm wrong, what can I say?
Nah, its just ALOT easier, more suggested it seems than kinda not.
Requiring 1 blockid/whatever for a fluid instead of 2.