I guess it`s very subjective. Very few bands can play very brutal without sounding like shit. Nile are very good with playing fast, brutal and heavy and still sounding good.
Devourment sounds pretty brutal like a few other bands playing the same kind of music.
I still prefer Nile before bands like Mortician and that stuff.
Emperor, Setherial and a few black metal bans delivers more evilness than many brutal death/grindcore bands i think.