Not really, unless I'm in just a horrible mood and even then I MUST be able to hear something with at least a touch of melody interspaced with the more extreme bands out there. Truth be told, the most extreme I can listen to over and over isn't really Emperor, Morbid Angel and the like. There are plenty of extreme harsh bands (death/thrash/viking/black) that toss in groove or melody that makes the extreme parts tolerable for extended periods. Carpathian Forest, The Crown, Moonsorrow, even Naglfar and many, many more.
If the "extremeness" is too straightforward without melody and catchiness, or even variation, then it's tough for me to listen to for extended periods of time.
For my understanding of what "Brutal" Death and "Extreme" Black metal is, the answer is no.