Until now I've always held a "Socionics could be accurate... but there's really no way of knowing" stance. I was willing to entertain the idea, assuming it's true for the sake of conversation. I didn't see any good reason not to. After all, it's an interesting theory. Plus it's the main topic of discussion here, and this forum has been pretty much my only social outlet for a while.
I think there's something to functional preferences, but overall I'm leaning towards the "it's all bullshit" vote. It seems ridiculous to think that there's SIXTEEN types, and every single person in the world fits into one of those sixteen types, and everyone of each specific type uses each of the functions in a specific way according to what type they are. While some people possess traits that seem to be a perfect fit for a type, overall there are just too many variables in human nature for every person in the world (or even most people, or just the healthy people) to fall neatly into one of sixteen categories. I do not believe that this can be explained by differences in environment, subtypes, cross types, etc.
That is all.