I think using the term "metal" is wayyyy too broad for what this thread is trying to accomplish.
<> Metal in the days of Metallica and Iron Maiden could definitely appeal to a wider variety of people than modern death metal/all the other crazy sub-genres.
<> What we call "hair metal" today, was basically at the same level of Lady Gaga and Katy Perry electro-pop today.
I'm an F. I love metallica (all of their songs and phases). I do not like "modern" metal with all of its crazy sub-genres. I think Metallica is definitely a very "thoughtful", "passionate" and "inquisitive" style and band. If this means F or T? Who knows.
I actually think metal probably correlates to something like being Limbic over Calm. Metal is often about being against the establishment, people being against you, not fitting in, and it all sounds somewhat neurotic when you compare it to some of the happy-go-lucky pop.