I don't have a preference, some of my favorite opeth moments are mello and "brutal" as you put it. My favorite "brutal" moment is the ending verse of 'April Ethereal.' "The rain was waving goodbye, when the night came the forest folded its branches around me, something passed by and i went into a dream, she, laughing and weeping at once, "Take me away!" I dont know how or why, and i'll never know when." The way the guitars and drumming go along with that verse, and the power in his voice just make it breathtaking to listen to. As for any mello parts, right now, it's hard for me to decide. I recently burned a cd with some of Opeth's more mello songs like Harvest, Face of Melinda, To bid you Farewell, Credence, and Benighted. I'd have to say there are some amazing mello parts in The Moor that i enjoy, though.