If you happen to have time to do it, I'd highly recommend going to YouTube and doing a search for "gravity blast" or "blast beats."
There are a bunch of videos, both amateur (mostly amateur) and professional quality of heavy metal drummers both good and not so good to check out there. The gravity blast videos happen to all be fairly good since most people won't even film themselves until they can get a decent gravity blast (those things are tough!).
Go for it and enjoy, ye heavy metalians!

