For years, I taught drum lessons at a place called Drums Unlimited in Winnipeg. All those hours with students help me through university. I bring this up because back then, all of us--students and teachers alike--didn't have many people to turn to when it came to metal.
Kevan Roy, the ex-drummer for Mastery, has just launched a new instructional website designed to help drummers perfect their metal skills. Having looked through it, I wish I had had this as a resource in my teaching days.
If this is where your headspace is at, give this a look. It may change everything about the way you play.