**** yeah. There are plenty of death/doom bands, but sadly few blackened sludge ones. I really can't think of a band which has nailed both genres so well, let alone combined the two so seamlessly. I see Coffinworm as sort of a new-age Celtic Frost, with Eyehategod and Darkthrone replacing Motorhead, Black Sabbath, and Discharge. Their first album is also well worth a listen, though it's not as sophisticated, and sometimes falls back on repetitive droning a bit too much. This album definitely raised the stakes for the band, and might just be the defining blackened sludge release. Totally waiting to see where they go from here.
Next rec...
Coffins -
Buried Death