I've seen them live four times and yes, they are absolutely horrendous. They are nearly as bad as Lamb of God, who I have seen live twice. Most American bands cannot pull off screaming vocals. Not only that, but the bass lines never blend with the drums, or even create any sort of ambiance. The lyrics usually suck as well. If you really want that type of music, look elsewhere for bands like In Flames, Soilwork, Trivium (heh, they're American), Dry Kill Logic (also American), Eluveitie, The Haunted etc. Gothenburg bands seem to have a solid grasp of this style. Most of the American hopefuls are merely generic-jammers.