I would say the difference between "Brutal" DM and regular DM is Brutal DM is more, well, BRUTAL!! Lower, more gutteral vocals, more blast beats and speed.
Brutal death bands would be : Cannibal Corpse, Deicide, Krisiun, Hate Eternal
07/28-Cannibal Corpse (?)
08/09-Heavy MTL (?)
08/10-Heavy MTL (?)