I'll be to the point: if you like the heavy stuff, go buy Soulfly's new album Dark Ages right now. Go listen to the tracks on Amazon.com if you're not quite sure. This is one of the best metal albums I've heard in a long time.
This is Max Cavalera's 5th studio effort with his Soulfly project. It sounds like he's finally achieving the "sound" that he's been striving for after leaving Sepultura. Dark Ages has the South American, tribal-metal flavor that the other four has, but this one is the heaviest. It has remnants of old Sepultura in there, but the bottom line is that the riffs are heavier and faster than the older Soulfly. Imagine a tribal-flavored Master of Puppets written in the 21st century.
This CD hasn't left my main rotation in my car and at work for a week now. Normally I toss a new CD onto the shelf after listening to it for a day or two because it gets boring. I can't put this one away. Go buy it. Unless drop-tuned speed riffs under a chorus of "RRRRRRRROOOOOOOOOOOOOGHGHGHGHGHGHGHGH" doesn't suit you.