I never realized that there was such a thing as "black metal", but sure enough, it appears to be a very well defined genre. I've heard some "Meshuggah" in my day , but even that does not qualify it seems (I think that is more "death metal"). Porcupine Tree, one of my more recent favs, they would be considered more progressive metal I think...they tend to operate in multiple gears from the highly melodic and psychodelic, aka early Floyd, to near death metal at times, particularly in their more recent work. I find the ultra metal stuff to be more effective and interesting when juxtaposed against more melodic themes within a single composition. I'm very much into the philosophy of ying and yang and like the prog metal groups like Porcupine Tree who know how to mix it up.
I would agree that revealing speakers like Thiel would probably work very well for metal in general.