FWIW, I find the DCNH subtypes vastly more useful than the two-subtype system, which is so vague and inaccurate as to be useless. My opinion, though.
The DCNH subtypes have an element of how you present yourself initially. For me, the first thing I can spot in someone is their temperament, since that's always the most visible aspect externally. Similarly, irrespective of base type, each DCNH subtype has very specific external characteristics, so it's occasionally possible to pick out their subtype before you've settled for sure on their base type.
The vast majority of people I snap-type though I wouldn't even have a clue as to their subtype, though. Usually it's only people I know personally, and within those the people I know better.