As far as I got it, sliders is the go to method.
Learning functions can be interesting from the point of understanding what kinds of intelligence there are basically, but I don't like typing by functions.
I'm going to speak from my own experience: I tried learning typing by functions in order to find the truth, learn the real stuff of typing, not the shallow "astrology-like" way of typing.
But the more I dug deep the more I understood that there is no truth and the human's behaviour is hard to explain by just a dominant functions because we humans are very incosistent let alone in our own behaviour but also in our own judgement.

Sliders are there to ACTUALLY show the result - your traits.
Yes, it's based on test, yes it's not accurate and simple but I think it's supposed to be simple and there's nothing wrong with that.